ARTIFICIAL BONE
Susan Liao and her colleagues from national university Singapore (NUS) have created artificial bone from an inorganic material with a nanostructure similar to the structure of natural bone.
Human bones consist mainly of nanocrystals of hydroxyapatite (65%) and collagen (25%) (and there are also springs there). In dentin this proportion is slightly different - 70% and 20%.
Scientists decided to make artificial bone from mineralized collagen, a biocompatible material that can become an excellent basis for implants and prostheses. At the same time, they developed a method for producing nanocomposites with different concentrations of collagen and bone carbonates (they designated this material as nCHAC).
The researchers were especially interested in the question of what would happen if the proportions of the ingredients changed. It turned out that by manipulating the initial solutions and, accordingly, the concentrations of carbonates and collagen, it is possible to create nanocomposites of different morphologies. In particular, with nCHAC crystals of different sizes and shapes. They formed needles that gradually shortened and formed spherical particles. It was similar to the formation of real bone, the authors of the experiments say.
And because of different structures The mechanical properties of the bone also changed. Thus, the new method can help in the creation of artificial biomaterials intended for a variety of operating conditions in the body and for prosthetics of various bones, the researchers believe.
For now, the structure of the resulting bone is not entirely identical to natural bone, but in the future, Liao intends to use her method to reproduce the same nanofibers that are observed in real bones.

Homologous bone graft bank

Porous structure - like natural bone

Pore ​​sizes play a decisive role in the osseous integration of the implant. Orthoss has natural system pore, which promotes bone restoration through the sprouting of blood vessels and migration of bone cells. The pore size varies due to its natural origin and is on the order of 100 microns.

Inner surface - like natural bone

Thanks to the intensively developed three-dimensional network structure of the connecting pores, the internal surface area of ​​the material is more than 90 m2/g and the internal space of Orthoss closely matches the human spongy bone. This provides a larger area of ​​contact between the implant material and the newly formed bone.

Crystal structure - like natural bone

The inorganic basis of human bone is the smallest crystals of apatite. Orthoss' unique manufacturing process maintains a crystalline structure similar to human bone. This facilitates the integration of Orthoss into the natural bone repair process.

Chemical composition - like natural bone

Compared to synthetic materials in Orthoss, biological apatite has fewer hydroxyl groups and more carbonate ions. The ratio between calcium and phosphate ions is 2:1, which is exactly the same as human bone.

Artificial bone can transform into ligaments

A team of researchers led by Professor Andres Garcia from the George W. Woodruff School of Mechanical Engineering at the Georgia Institute of Technology was not only able to create artificial bone that transitions into softer tissue, but also transfer this technology in vivo in a few weeks.

Scientists managed to create such tissue using a three-dimensional polymer scaffold, at one end of which a high concentration of the transcription factor Runx2 was maintained, and towards the other end, the content of the transcription factor gradually disappeared, i.e. The researchers created a precisely calculated spatial gradient of this factor. The entire scaffold was then uniformly populated with skin fibroblasts. As a result, fibroblasts that entered the part of the scaffold containing a large amount of the Runx2 factor became bone tissue, and those that populated its opposite end, devoid of this factor, became ligaments and tendons.

If the proposed technology passes the necessary tests, one of its applications will be operations on the anterior cruciate ligament (ACL). The fact is that at present, surgical treatment of ACL injuries is not very effective, since it is impossible to reproduce the transition from bone tissue to the tissue of the ligament itself.

According to researchers, every organ in our body has a complex, heterogeneous structure. Therefore, the ability to artificially create tissues that best replicate the properties of natural ones is a huge leap forward for tissue engineering.

What is a bone? Information about the bone

Based on their shape, bones are divided into long, wide and short. Long or tubular bones are those in which the length greatly exceeds the width and thickness; they have a more or less cylindrical middle part, a body (Corpus s. Diaphysis) with a cavity inside and 2 ends or epiphysis (Extremitates s. Epiphyses), which are always wider than the body and covered on the articular surfaces with a layer of cartilage, located in the limbs and more or less curved. In wide bones, two dimensions predominate over the third; such bones serve primarily to form the walls of cavities enclosing various organs(skull, thoracic, pelvic cavity) and can be flat, curved, concave, etc. In short bones, no one dimension predominates significantly over the others; These are irregular, rounded or polygonal bones (eg vertebrae, carpal bones and heel bones).

The surface of the bone can present various depressions (grooves, pits, etc.) and elevations (corners, edges, ribs, ridges, tubercles, etc.). The irregularities serve to connect bones to each other or to attach muscles and are more developed the more developed the muscles. On the surface there are so-called “nutrient openings” (Foramina nutritiva), through which nourishing and blood vessels enter the bone.

The bones are divided into dense and spongy bone matter. The first is characterized by uniformity, hardness and makes up the outer layer of bone; it is especially developed in the middle part of the tubular bones and becomes thinner towards the ends; in wide bones it consists of 2 plates, separated by a layer of spongy substance; in short ones, it covers the bone from the outside in the form of a thin film. The spongy substance consists of plates that intersect in different directions, forming a system of cavities and holes that merge into a large cavity in the middle of the long bones.

Chemical industry Chemical news stories

Since ancient times, ivory has been valued as a material for making all kinds of artistic products. However, this material is expensive and rare, so attempts have also been made to make artificial ivory for a long time. At the same time, they tried to give the resulting material not only the appearance Ivory, but also to provide it with appropriate mechanical properties. To do this, it was necessary to repeat its structure with a certain degree of approximation. Here we will not touch on the structure of teeth (and elephant tusks are overdeveloped teeth), we will only say that teeth are a kind of composite material, some components of which give it hardness, while others perceive tensile and compressive loads. They strive to give the same structure to homemade ivory.

Of course, where high mechanical qualities of a substitute material are not required, it is enough to maintain its external resemblance to the natural original, which makes it possible to simplify the technology of its production. So, when choosing one or another method of obtaining a material that imitates ivory, one usually proceeds from the expected conditions of its use. Note that in all cases considered below we're talking about about imitation of unpainted ivory - white or slightly yellowish. If there is a desire to have a colored “bone”, it is not difficult to realize it by adding a dye of the appropriate nature to the still liquid ornamental mass (aniline dyes are suitable for almost all of the above compositions).

Now let's move on to specific practical recommendations, allowing you to make “ivory” at home. I will add that all the recipes proposed below were used for counterfeiting ivory about a century ago, when the production of plastics was just beginning to develop.

Recipe No. 1. One part of white shellac (a natural resin of animal origin produced by insects - packbugs) is dissolved in four parts of a 14% aqueous ammonia solution with continuous stirring in a tightly closed vessel (here you will need a mechanical stirrer, but you can do without it, ensuring mixing the components by simply shaking the vessel). The temperature inside the vessel is maintained in the range of 35...40°C. The dissolution process takes about 5 hours. By the end of this period, a syrup-like solution is formed, to which five parts of dry zinc white are added. The mixture is thoroughly mixed and ground until a completely homogeneous mass is obtained. The latter is slightly heated until the smell of ammonia completely disappears, and then dried in air, deposited on a glass plate. The dried (but not dry) mass is molded.

You can do it differently - thoroughly dry the mixture, grind it into powder and press products from the powder (at a pressure of 16 atm and a temperature of 125...130 ° C). The quality of the products in this case will be higher, but ensuring the required pressing mode at home is not so easy. I also note that the composition of the components here and below is given in parts (by weight).

Recipe No. 2. Prepare a mixture of 20 parts borax, 10 parts potash, 38 parts lithopone (mineral paint based on zinc sulfide and barium sulfate) and 6 parts asbestos. Melt all the components, add 9 parts of dry zinc white to the melt and, keeping the mass liquid, mix until homogeneous, then pour into molds previously greased from the inside with oil.

Recipe No. 3. Finely chopped white paper is boiled in water for several hours, ground, strained and, spread out in a thin layer, dried in air under stretched gauze. The result is a light fluffy paper mass. By mixing it with water, a homogeneous, not very thick fibrous porridge is prepared.

Two solutions are prepared at the same time, and for one of them they are dissolved in pita hot water 100 g of light grade wood glue, after which the solution is filtered through a cloth, and for another, 50 g of potassium alum is dissolved in a liter of water. Next, in a large bowl, mix 8 parts of paper porridge, 3 parts of warm glue solution and 8 parts of also warm water. Add 10 parts of clean, lump-free alabaster here and stir the mixture until it becomes completely homogeneous. After this, add 8 parts of a warm alum solution and mix everything again.

After greasing the metal molds with oil, pour the resulting mass into them and allow it to thicken. Then the molds are covered with canvas and their contents are pressed. The squeezed water passes freely through the fabric, while the remaining components of the pressed material are retained in the mold.

After 20...25 minutes after pressing, take a mallet, knock the castings out of the molds and quickly wash them off the oil in hot water. Then the products are dried and dipped into heated colorless floor polishing mastic so that the surface of the material is well saturated with this composition. After this treatment, drying follows. When the “bone” is dry, take a soft brush or woolen cloth and polish the surface of the material with gypsum powder until it acquires a characteristic shine.

The ornamental mass obtained by this method is appearance very similar to layer bone, but is only suitable for making various types of jewelry and inlay.

Recipe No. 4. Perhaps one of the most quality materials, imitating ivory - neoleukorite. It is easy to grind on lathe, milling, drilling, sawing. The combination of the availability of raw materials and the great external resemblance of the resulting material to ivory makes this recipe the most attractive of all the recipes given in this article.

Mix 100 parts of phenol, 185 parts of 40% formaldehyde, 75 parts of 40% sodium hydroxide solution and 38 parts of 50% lactic acid. Place the mixture in a glass flask or other vessel that is resistant to acids and alkalis, and place the mixture in a water bath. Close the vessel with a stopper with a reflux condenser installed in it (if you need to condense the vapors and return them to the reaction zone, use reflux refrigerators— with an upward flow of water; when distillation or distillation is carried out, direct “downward” condensers are used). The installation diagram is shown in Fig. 1. The mixture is heated for 3 hours at a temperature of 60...70°C.

The mass formed during the cooking process is dehydrated under vacuum, while continuing to heat it in a water bath. The vacuum is obtained using a water-jet vacuum pump (Fig. 2). An hour and a half after the start of dehydration, 38 parts of 50% lactic acid are added to the vessel, after which the vacuum pump is reconnected to it.

When the contents of the vessel become viscous and large bubbles appear on its surface, the mixture, without cooling, is poured into molds, and they are placed in a vessel with pure mineral oil. This vessel is placed in an electrically heated sand bath and the mixture is heated for three days, gradually raising the temperature from 75°C to 100°C.

By the end of the specified period, the hardened mass is easily separated from the walls of the molds (the resulting product can be subjected to mechanical processing).

Recipe No. 5. Dissolve 4 parts of gelatin in 20 parts of warm water, add 4 parts of slaked lime, 10 parts of kaolin and 2 parts of dry lead white into the solution, mix everything thoroughly. The resulting mass is poured into metal molds and pressed. The castings removed from the molds are dried and varnished.

Recipe No. 6. Crushed dry wood glue of light grades

soldered into a vessel with a solution of aluminum sulfate or acetate (one part salt to four parts water) and left to swell. The swollen glue is dried and pressed. The resulting mass is cut and ground like bone.

Magazine "Do it yourself" No. 3-04.

Black mordant for horn

As is known, horn products, such as combs, buttons, cufflinks, etc., are often painted black to imitate them as more expensive varieties. There are several ways to do this:

A) Horn products are soaked in the following solution, which is prepared in the cold: 8 parts of mercury are dissolved in 8 parts of concentrated nitric acid and 32 parts of soft water. The products are left in this mordant overnight, after which they are removed and washed with water until the wash water is no longer acidic. This treatment turns the combs red, and if more concentrated solution mercury - brown. After this, the combs are transferred to a weak solution of liver sulfur (1 g per 1 liter of water) for 1-2 hours. The now black-colored combs are washed first with clean water, then acidified with vinegar and finally with clean water. After this they are dried and polished. With the help of such processing, horn products are obtained that, according to experts, are not inferior to products made from buffalo horn. Polishing painted objects must be done carefully, as the mordant does not penetrate deep enough into the horn.

b) Horn products are placed in a cold place overnight water solution lead nitrate (1:4 ratio), after which they are placed for half an hour in a 3% solution of hydrochloric acid and finally washed with water. If the coloring turns out to be uneven, the operation is repeated again. This excellent mordant significantly increases the value of horn products.
Gray mordant for horn.

To paint the horn gray, first boil it for 15-30 minutes in a saturated solution of lead sugar, then rinse it in clean water and put it in a solution of nitrate, mercuric oxide, heated to 60+C for 20-25 minutes. This method is not suitable for combs, since the teeth suffer from cooking.

Red mordant for horn

To dye the horn red, the following method is recommended. The light horn is boiled for 30 minutes in a solution consisting of 20 g of safflower and 10 g of soda in 0.5 liters of water, and then placed in a weak solution of tartaric acid for half an hour. Then they take it out and, after washing, put it again in a safflower solution and then again in a solution of tartaric acid, and so continue until the desired color is formed. This way it is easy to get all shades from the lightest to the darkest red. You just need to remember that the tartar bath should always be the last.

Tortoise horn mordant

If you want to give horn products a tortoiseshell color, then use the following method. Horn products are first treated with diluted nitric acid (1 part to 3 parts water) at a temperature of 30-35 + C and then etched with a mixture of 2 parts soda, 1 part freshly burnt lime and 1 part lead litharge. The effect of the mordant should last no more than 10-15 minutes for the spots on the horn to turn yellow-brown. After this, having washed off the mordant from the horn, wipe it with a cloth and place it in a cold dye bath consisting of 4 parts of mahogany decoction (10+ according to Baume) and 1 part of sodium hydroxide solution (20+ according to Baume). Then the horn is removed from the bath, thoroughly washed with water and polished after 12-16 hours. A dye decoction is prepared by boiling 0.5 kg of fernambuco wood in 4-6 liters of water. If you add tin salts to the mordant, you get a bright red hue.

Aniline mordants for bone

Etching bone with aniline dyes is easier than other methods, since it is carried out in a cold bath, which eliminates the possibility of cracking of objects. Etching is carried out as follows: objects are placed in a basin and so much water is poured in that they are completely covered with it. Then 2 teaspoons of vinegar and about 1 g of paint are added to the liquid, and it doesn’t matter whether the latter is soluble in alcohol or water. For the desired shades, select suitable aniline dyes or combine them from several. Bone objects are left in the liquid for 4-8 hours and removed immediately when the desired tone density is achieved. Then they are washed with water, dried and polished with Vienna lime and soap. Alcohol varnishes and polishes should not be used here, as they can dissolve the paint on the surface of the bone.

If you need to paint an ivory billiard ball in two colors with parallel stripes, then, already polished, it is clamped between three thin sticks inserted vertically into a small board, covered middle lane oil varnish and paint one segment first, immersing the ball together with the board into the appropriate aniline mordant. Having finished painting, let it dry, and clean off the varnish with turpentine and paint this part in the required color, having previously covered the finished part of the ball with oil varnish. Proceed in a similar way if the ball needs to be painted on three or four sides.

Whitening ivory

To return yellowed ivory to its original whiteness, one of the following methods is practiced. The ivory is covered with a thin layer of turpentine and exposed to the sun for 3 or 4 days. Another way: ivory is immersed in hydrogen peroxide for a while, after which it is wiped dry. To speed up the bleaching process, the bone is subjected to
exposure to the rays of a blue quartz electric lamp. With both methods, the bone becomes completely white.

Coloring billiard balls

To dye billiard balls red, they should be immersed in vinegar, in which cochineal has been previously soaked, and boiled in this vinegar for several minutes. Then, to give the color a deeper shade, the balls are transferred for 10-15 seconds to a very weak solution of potash. After keeping the billiard balls for 6-8 hours in vinegar or alum solution, they can then be easily painted an excellent yellow color, for which it is enough to dip them in an alum saffron decoction for a while. Green coloring is achieved by immersing the balls in vinegar, in which 1 part ammonia to 3 parts verdigris is dissolved. If you then transfer these balls into hot potash lye, they will turn blue. Finally, to paint billiard balls black, they should be kept for several minutes in a hot decoction of logwood (blue sandalwood), and then transferred to a solution of acetic acid.

Silver polished ivory

Ivory items can be given a very impressive shiny silver polish. Here is a very simple method: after finishing, the ivory product is immersed in a weak solution of silver nitrate and, as soon as it turns dark yellow, it is immersed in clean water and exposed to the sun. After about three hours the bone turns completely black; then it is carefully rubbed with rawhide, after which the bone acquires a beautiful shiny silver polish.

1. Imitation ivory according to Giatt. First, prepare a solution of 8 bleached pure white shellac and 32 ammonia (0.995 specific weight), for which both components are constantly shaken for 5 hours. in a rotating cylinder; If possible, the temperature should be kept at 37.5°. After this time, complete dissolution occurs and the solution has the consistency of liquid syrup. 40 zinc oxide of good quality is added to this solution and mixed by hand as best as possible. The mixture is placed in a paint grinder and ground. Ammonia water, which has already served its purpose, is best evaporated by heating. The mixture is dried on glass boards in air.

After the ammonia evaporates, only zinc oxide and shellac remain, from which the products are prepared. They are completely dried, milled again in a completely dry mill of a suitable design, and the resulting fine flour is filled into molds.

In molds, pressure can reach up to 160 kg per 1 cm2, and temperature up to 125-137.5 °C. If you want to color an object, you can add the dye either before the first grinding to the solution, or before the second grinding to the dry mass.

2. Imitation of ivory according to Hepher. The binding agent for this mass is ammonia solution casein, which is prepared from 20 casein and 5 ammonia.

The following is added to the solution: 42 caustic lime, 15 alumina acetate, 5 alum, 120 gypsum and 10 vegetable oil.

The oil is added last. If they want to make dark-colored objects from the mass, then instead of acetic acid alumina they take 75-100 tannin. When the mixture is well kneaded and forms a homogeneous dough, it is passed through rollers to form plates of any size and thickness. The plates are dried and pressed into preheated molds, or they are reduced to a very fine powder that is filled into heated molds and subjected to high pressure. The items removed from the molds are placed in the following bath: 100 water, 1 light wood glue and 10 phosphoric acid.

Objects treated in this way are dried, polished and coated with a white shellac solution.

3. Imitation ivory according to Garras. The ivory mass consists of wood glue, cellulose and alabaster. When casting, it is best to use metal molds, as they give sharper impressions than molds made of glue or rubber. All kinds of decorations, furniture inlays, album covers and similar small items are made from this mass.

The adhesive solution is prepared from 100 g of light glue in 1 kg of water and filtered through a cloth. Cellulose slurry is prepared by pouring 50 g of well-bleached cellulose, 3.5 kg of water and rubbing well until a uniformly thick slurry is formed. Then separately dissolve 50 g of alum in 1 kg of hot water and allow to cool to moderate warmth; If the solution is allowed to cool very much, the alum will crystallize.

The metal mold is first thoroughly greased with good light oil or a mixture of equal parts goose and pork fat. Then, in a large clay vessel, mix 75 adhesive solution and 200 cellulose slurry, add 200 water and 250 rarely crushed alabaster, previously sifted through a hair sieve. All this is ground until the alabaster is completely dissolved and a homogeneous mixture is formed. After this, add another 200 alum solution and stir thoroughly. The resulting mass is poured with a spoon into metal molds. To prevent the liquid mass from spilling out, the molds are equipped with iron or wooden frames containing a design or decoration. When the mass is poured in, shake the mold for a while so that the mass is evenly distributed and there are no air bubbles; then the mold is left alone until the mass begins to thicken. At this moment, the form is applied with a damp piece of canvas, a wooden or iron board included in the frame is placed on it, which should be twice as high as the frame itself, and placed under a press and very carefully pressed, and the water released under pressure is poured out. The mixed alum causes the mass to quickly harden and does not allow the glue to stand out, so that with slow, uniform pressing, only clean water flows down. When the mass is sufficiently compressed, the mold is allowed to stand for another quarter of an hour, and then the cast item is knocked out using a wooden hammer. The item removed from the mold is immediately placed in a clean, hot water bath to clean it of any fatty particles. The item is then dried in a drying oven, after which it is placed in a boiling bath of equal parts wax and stearin so that it is completely saturated. In this state, the item is allowed to cool completely and rubbed with a soft bristle brush and sprinkled with white talc until an ivory shine appears.

4. Mass for billiard balls. Allow 90 carpenter's glue to swell in 110 water, heat it in a water bath and add 5 kg of heavy spar, 4 kg of chalk and 1 kg of boiled linseed oil. Small sticks made from the same mass are immersed in this mass, the stuck mass is allowed to dry, immersed again, and so on until a roughly shaped ball is formed. When the balls are completely dry after 3 - 4 months, they are suitably turned on a lathe, immersed in a bath of alumina acetate for 1 hour, dried and polished again.

5. Blood and bone mass according to Palmer. Palmer uses not pure bull's blood as a binding agent for his mass, but that component, which remains when the blood is allowed to stand for several hours, and then the remaining liquid part is drained. The blood clot thus obtained consists of coagulated fibrin, which appears dark brown in color due to the presence of blood globules.

To make a moldable mass from this substance, it must be dried at room temperature to such an extent that it can be turned into powder. The powder is then sifted through a fine sieve and pressed vigorously in heated molds. Objects made in this way are dark brown in color and can be polished like rubber.

The pressure to which the mass is subjected depends on the purpose of the object being pressed. In some cases, when it comes to the production of very stable and durable objects, such as furniture casters, knife handles, tool handles, a pressure of 40 tons is applied during pressing, which takes place at a temperature of 95 to 150 ° C . Such strong pressure can only be obtained by using a hydraulic press.

Despite the application of strong pressure, the mass consisting of only blood is very brittle. To avoid this drawback, bone meal and an adhesive solution are mixed with the blood, which serves as a binding agent for the blood. The proportion between blood powder and bone meal is approximately 5:1, and the glue, which should have the consistency of milk, is used to take a tenth of the volume of blood. By adding various coloring substances, the mass can be colored in different ways. Blood and bone mass is very suitable for making knobs for canes, door handles, knife handles, as well as for making small objects - lighters, etc. If an object made from such a mass had to lie in dampness for a long time, then it may have begun to would become moldy; but this can be easily avoided if you add 0.005 of its weight of burnt alum to the mass and only then press it in molds. Alum vigorously counteracts the development of mold and rotting microorganisms.

Real bone carving is a very expensive art form that takes a long time to learn. Therefore, you can more often see all kinds of imitations of bone carving. Today I want to show two of my simulation options, which I came to quite recently:

Box “Savannah” - imitation of bone carving on a dark background;

Panel hanger - imitation of bone carving on a light background.

1. Box “Savannah” - imitation of bone carving on a dark background

To work on the “Savannah” box we will need the following materials:

Making a box made of wood or MDF;

Water stain;

PVA glue;

Rough relief paste;

Acrylic lacquer;

Wood putty;

Silicone molds, synthetic brushes, a bottle for paste, a cloth or napkins and a good mood!

The first thing we do is cover the workpiece with stain. (Before applying, sand the surface with sandpaper if there are any unevenness or chips on it). After drying, it is necessary to sand the raised fibers and dry them again. The stain dries quite quickly.

While the wood is drying, we begin work on creating the frame and corners. For this I used silicone molds. To create the corners, I chose a round mold, made a mold and cut it into four pieces that fit perfectly into the corners.

I always use Das self-hardening clay when working with deep molds.

For those who are doing it for the first time, I will describe the process. We tear off a small piece of clay, knead it and place it in the mold. Cut off the excess with a sharp wallpaper knife. There is no need to wait for the clay in the mold to dry. Carefully take out the resulting cast and glue it to our workpiece.

The mold for the harnesses turned out to be not the best best quality, so the resulting tourniquets upset me somewhat. But since there was no other option, after thinking a little about the manual labor of an artisan, who has the right to inaccuracies, I decided to continue with it.

So I made a frame in the form of ropes.

I also sculpted two charming elephants and, placing them under the crown, glued them on PVA. We glue all the clay elements in their raw form directly onto PVA.

I did the same on the sides of the box. Clay takes a long time to dry, so I usually leave it overnight and continue decorating in the morning.

It seemed to me that the volume from the relief paste was not enough, so I decided to add a little of it and give the tree a slightly convex-sloping shape. To do this, I diluted the putty with PVA glue in approximately a ratio of 1:3 and transferred the resulting mass into a special tube with a spout. The mass turned out to be quite soft, the consistency of sour cream, so I quickly and easily passed it over the entire crown, trunk and branches.

After drying, satisfied with the result of the added volume, I varnished the entire product on the outside with about 4-5 layers of semi-gloss varnish with intermediate drying.

While the outside of the box was drying, I spread some ivory paint and coated the inside, varnished it and left it to dry too.

Now that everything is dry, let's get to the fun part! Now we still have in front of us a simple box with stucco, which we have to turn into ivory. To do this, take a little brown paint (I use “Acrylic Art” Burnt Umbra) and dilute it heavily with water.

We begin to do the patination. We begin to pour the resulting brown water with a brush into all the recesses and on top of all the elements. Wipe off excess with a cloth or napkin. It is this technique that will turn simple stucco into ivory, so it is important not to overdo it.

Don't be afraid if water flows from the stucco onto the stained surface; it is reliably protected with varnish. Next, we dry everything properly, naturally, and finish it with acrylic semi-gloss varnish in two or three layers.

Don't forget to age the interior, too! To do this, take a little of the same brown water on a thin brush and run it along the corners and perimeter of the bottom. We also remove the excess, dry it, and then varnish it.

Well, the master class has come to an end. I hope you liked my result, I will be glad if you want to apply the knowledge gained in your work.

I had never done imitation bone carving on a dark background before, it was a completely new experience for me. I found him more interesting and attractive. The bark of a palm tree, specially brought by me from Africa, was used as a photo background in the final photographs. I think it highlights the theme of elephants and the African Savannah very well.

2. Panel hanger - imitation of ivory carving on a light background.

To work on a panel hanger with imitation ivory, we will need the following materials:

Preparing a panel from wood or MDF;

PVA glue;

Acrylic paints “Acrylic-Art”: Burnt Umber, Titanium White;

Acrylic paint “Acrylic-Hobby De Luxe”: Warm Ivory;

Acrylic lacquer;

Self-hardening polymer clay;

Silicone molds, synthetic brushes, a bottle for paste, a cloth or napkins and a good mood!

Modeling gel "TAIR" or paste Sonet.

When starting to work on this panel, I already had some experience in creating an imitation of smooth and relief carving on bone. Therefore, I decided to try to imitate the third type of thread - through. I looked at a lot of images, read about this direction and realized that through threads can be used not only as an independent “wall”, it can also be leaned against the base.

Having chosen the silicone mold I liked based on the pattern of the openwork, I filled it with Sonet paste and left it overnight. It is not necessary to fill in Sonnet; you can use modeling gel or TAIR diluent paste. I have already cast openwork lace from Tair modeling gel many times before; I really like the durable and flexible result. The resulting castings can be cut, painted, varnished, and screwed onto any even round surface. Such materials must be poured and left in silicone form for a few hours.

So we have two castings that took a day to make. Let's get to work.

The first step is to sand the workpiece, especially at the ends.

Next, let's start making a frame from strands. We tear off a small piece of clay, knead it and place it in the mold. Cut off the excess with a sharp wallpaper knife. There is no need to wait for the clay in the mold to dry. Carefully remove and immediately glue the resulting clay cast onto PVA glue. Lightly and carefully press the flagella onto the workpiece with your fingers. After some time they will stick and we will leave them to dry. Clay takes a long time to dry. There is no need to dry it with a hairdryer, it may crack.

In order not to waste time, we apply the openwork to the workpiece, make marks along the upper arch and cut off the excess with scissors. We try it on, if everything is satisfactory, we lubricate the workpiece with glue and glue the openwork castings. You don't need to do anything to fix them.

I wanted this panel to be some kind of architectural element, so I looked at my castings and found a mascaron mold that was ready for testing. This was a test casting from Sonnet paste, the result of which I was not satisfied with. The cast mold took a very long time to dry, 2-3 days, shrank and the face of the mascaron itself was damaged. Therefore, I no longer use this paste for deep castings; it is only suitable for shallow forms. But since, according to my idea, the panel was made in an architectural style, it was precisely this not very successful casting that came in handy for me. There was already a trace of time on it.

But having tried it on the blank, I realized that it was too small and was getting lost, so I took another mod with a bas-relief image and made a cast from it using clay, which I glued to the blank with glue, and laid the mascaron on top of it and glued it on top. Using the same principle, I made and glued a clay garland.

Now all the finished elements need to be dried thoroughly, about 8 hours

We cover the entire product on all sides with Acrylic-Hobby De Luxe Ivory paint. Let it dry and apply two or three layers of varnish again.

When all the elements have dried, we begin to create the effect of carved bone. To do this, dilute the brown paint with water and begin to fill all the recesses. Don't forget to coat the entire surface to give the desired shade. Carefully remove the excess with a cloth or napkin. After thorough drying, we cover everything with a finishing semi-gloss varnish, dry it, and admire the finished result!

If you want the end result to be completely new, pay close attention to the details on the impressions and castings. I wanted the mascaron, garland and rope frame to look ancient and weathered, as they are protruding architectural elements. Therefore, I did not need great accuracy for this work. And, relatively speaking, the damaged nose was a plus, not a minus. But perfect for new job, it is still necessary to monitor the quality of the impression or casting and it is advisable to put one layer, no more, of glossy varnish on the most voluminous elements.

I hope you liked my version of the imitation through thread by bone and you can try it in your works without any problems!