- Inks used for collotype are different from the inks commonly used in printing, which are not suitable. They have very specific characteristics.
- Collotype ink is a very firm ink which must be softened at the spatula on the marble and its viscosity adjusted by the addition of a small quantity of linen varnish before being displayed over ink rolls. One collotype quality ink is an ink which at first is enough hardness. This light excess of firmness allows the precise regulation of its viscosity. This viscosity determines largely the quality of the printed image: intensity of the blacks, more or less the grey.
- A too flexible ink will veil the plate of gelatin, and we shall obtain only images tinted without contrast. It is what what occurs with an ink offset, lithographic or typographic which are too liquid ink. A too firm ink will produce images too much contrasted with insufficient halftones.
- We have to watch also to adjust the quantity of the inking to the plate. An ink excess will produce images globally too much darkened while an insufficiency of inking will produce images globally too clear. Take into account that the inking weakens according to the drawing – every sheet taking in its passage a certain ink quantity. To reload from time to time rollers with ink.
- They exist in basic colors, and the wished colors obtain classically by mixture. The number very limited by practitioners of this technique pulled the rarefaction of its manufacturing. The difficulties repeated to stock up of such ink led to us to assure the manufacturing (on sale in the shop). We can make specific ink, contact us.
- On the video below, you perceive the final phase of the manufacturing of the ink phototypie: the refining on crusher three-cylinders :