المواد الملونة ومواد الطلاء السميك ٣_a , من كتاب تكنولوجيا التصوير , د.م محمد حماد

Brown like walnut wood. It is composed of iron hydroxide mixed with manganese dioxide. This color took its name from the fact that the best kind is extracted from the land of Siena in the form of dry stone pieces, then roasted, so that it becomes of a stable and strong color ... but this depends on the degree of its resistance. One of the properties of this color is to mix with all white colors and fixed colors, but it changes if mixed with zingo-fry, metallic blue, and Prussian blue, and the paint of this pure color dries within about three days.

(B) Terra d'ombra naturale * Terra d'ombra naturale This color is one of the natural mineral colors consisting of iron and manganese hydroxide. It has a brown color that tends to be slightly greenish, but it is not a fixed color, as it is affected by light, and its color tone decreases and tends to calm if mixed with white colors. Experts advise using it pure or as a cover for other colors, and it dries in about four days if it is pure.

(C) Roasted shade clay *** Terra d'ombra bruciata From the name of this color we see that it is the same natural shade clay previously mentioned with all its elements with roasting or calcination to become more buried in its dark reddish-brown color as it becomes more solid and resistant. This color is like a natural shade mud, if it is mixed with oil, then it dries in about four days if it is pure.

(D) Terra di Kassel This color is also a natural mineral color. This clay is extracted from Kassel, and its color is dark brown... However, this color is not stable, and the degree of its stability varies according to the mines from which this clay is extracted, as its composition varies accordingly, and the darker the color, the higher its validity. Experts believe that it is always better to use this color purely without mixing it with other colors in order to give a deep dark color in which there is a sense of dark places... but mixing it with other colors loses its stability and weakens its strength. And you notice that this color is one of the slow-drying colors, as it dries if it is pure in about 18 days

(e) Asphalt construction * It is called bitumen, as it is made of bitumen or asphalt ... It is also called mummy construction, as some ancient mummies were treated with bitumen in later ages, and the outer surfaces of mummy coffins were requested with bitumen, and therefore they called it this name . It is a metallic color that results from the decomposition of nanomaterials, and the elements from which it is composed differ according to the nature of the land from which it was extracted. And because it has a bright, transparent, brown color, it is what tempts photographers to use it. Asfalto Bitume

This color has been used a lot throughout history... Today, artists have almost stayed away from it because it dries very slowly, or almost does not dry. Despite its beautiful brown color, which tends to be black, it needs a lot of caution in using it as one of the coloring directions, which cannot be supported, and often we see it used in the final layer of photography in order to give it a sense of antiquity.
For the preparation of bitumen, it is dissolved in turpentine oil with an oil that can dry at a low temperature, or it is first dissolved in turpentine oil, then acidified and ground in linseed oil to be harder and slower drying. It appears that the well-known Apelle varnish (which is a varnish odour) was made of bitumen, oil and resin, but we do not recommend using it.

(f) Bruno Van Dyek brown, either natural or from industrial mineral colors, and is prepared by calcination (roasting) of ferric sulfate (Ca) and it is of medium strength. This brown color is from a mixture of clay and is considered one of the strong colors, and it is used to obtain a cold black color Or to prepare cold gray shades if mixed with silver white.

Bruno di Vibert Bruno trasparente

Bruno di alizarina (I) built the bazarina *** and it is also called Bruno di robbia or Bruno di garanza, and it is a color extracted from calcination of a plant known as Rubriacee, and it is a color of great resistance and is used to prepare many photographic colors. This color is similar in its properties to all the properties of Lac Granza red, which is extracted from a similar vegetable origin, and it loses its color if mixed with silvery white. And if used pure, it dries in about ten days.

(g) Vibrate brown *** It is also called transparent brown, because the carefully prepared types of it have a special transparency that gives them a kind of beautiful warmth. This color is prepared from calcined iron oxide, which is one of the most resistant colors, and brown iron oxides are not affected by acids or heat, hence their use in anti-corrosion paints, but they do not prevent rust. This color is considered one of the best brown colors in photographic works such as Bani Mart, and if used pure, it dries in about three days.

(h) Bruno di Mart, which is iron oxide and is considered one of the industrial ocher colors that are prepared by Mart, in various degrees that differ according to the degree of calcination of this compound, which is orange, then red, then brown, then violet. It is considered one of the strong and completely stable colors and dries in three days if used pure.

(J) Aloe or Aloe built this color from the colors that were used extensively throughout history to give the final layer for painting, or it was used on surfaces in paintings before the beginning of painting. It is twice the resistance and is not used now. coverage

(k) Squid or captive brown * Seppia, which is the only brown color that is extracted from animal origin, and it is a cool color that tends to green and is characterized by golden transparency. Its name was taken from a type of aquatic organism from which it is taken, and it is known as captive, and it disappears in the sea in areas surrounded by grass, out of sight, and secretes a sticky substance that gives a color like ink. Therefore, this color is taken from the substance colored by the bodies of these organisms. Venice is seen by many
The Italian coastal cities on the Adriatic are a center for a wide trade of this fresh produce, which is dried directly after extraction in the sun and prepared with potassium carbonate, then the solution is filtered to separate the soluble matter. This color has a great value in watercolor photography, as it dissolves easily in water, but it is not easy to mix with oil colors, and it does not withstand light resistance, and therefore it is not used in the composition of the colors of oil painting.

e - blue dyes :

Blue colors are also divided into natural colors such as lapis lazuli blue, metallic industrial colors such as cobalt blue, ultramarine, Prussian blue, metallic blue, sky blue, and organic plant colors such as indigo blue, which is a color of special value in watercolor photography.

(a) Lapis lazuli blue *** Azzurro di lapislazzuli It is also called lazzulite or blue stone azzurro di pietra The reason for this name is because it is found by nature in the form of bright blue stones like glass called “lapis lazuli” in the rocks of some ancient mountainous areas. In Egypt, some eastern countries, Siberia, the Tibetan plateau, Iran, Argentina, etc. If these stones are genuine and pure, they are certainly in the highest degree of resistance and are not affected by external factors.The composition of this chemical color differs according to the nature of the region in which it is found, and the most important elements from which it is composed It is a silicate of aluminum, sodium and sulfur.

The ancients used this color for various coloring purposes, as it was used in the colors of varnishes. Shanini praised it and called it “the noble, beautiful color that is more perfect than any other color.” However, despite that, color factories rarely produce it due to the scarcity of the stones from which it is made. It is considered a rare gemstone. Therefore, it was possible to replace this color with artificial colors such as the color of ultramarine or the blue beyond the sea (the sky), and we will talk about it as it wears out. And if lazuli was used purely as an oil paint, it would dry in about three days. Cennini Oltremare

(B) Ultramarine blue *** Azzurro oltremare This color is one of the dyes with a blue color that is called after the sea or heavenly, as the sea takes on the blue color of the sky that reflects its blue on it. It is a compound of aluminum silicate and sodium sulfate, and it comes out by mixing kaolin, sodium bicarbonate and sulfur in an oxidizing atmosphere, which are complex mixtures of sodium aminosilicate, sulfides and double sulfides. Its colors vary according to the conditions of its preparation, some of which are light, dark, and medium.. The most important of which is sky blue impregnated with violet, which is solid in light, but its ability to prevent light from penetrating is weak. It cannot be mixed with lead dyes or lead driers that cause it to darken. Therefore, it cannot be mixed with silver white, Napoli yellow, and yellow.