COLLOTYPE INKS - The Mystery Revealed
Never one to miss an opportunity, I have added Caligo's Collotype Inks to the selection offered by Graphic Chemical & Ink. We have a small but loyal following of collotype artists using our Senefelder's Crayon Black Litho Ink, but now the possibilities are significantly expanded. Enjoy....
The underlying theory is similar to the same mad idea behind lithography: Oil and water don’t mix! With collotype, the science is pushed to a higher plane. Rather than having areas on the printing plate that are simply ‘Yes’ or ‘No’ in that they either print or don’t print, collotype has found a way of printing the in-betweens! Ink does not simply print or not print, it is applied to the paper in varying film thickness, to give a genuine continuous tone. Historically the process has understandably been interwoven with photography and is normally used with this kind of original.
The way it works in practice is like this: A glass plate is coated with sensitized gelatin solution which is ‘oven cooked’ to leave a wrinkled or ‘reticulated’ surface. The plate is then exposed under a reversed photographic negative. Light passes through the negative to harden the gelatin on the glass plate. However the areas of gelatin that are unexposed, remain soft and will later absorb water when washed. It is the hardened exposed areas that will repel the water and remain dry and become the ‘image areas’.
The differing hardness of the gelatin controls the water absorbency of the various tones across the plate. The washed glass plate can then be ‘inked’ with an oil based ink that will adhere in varying film weight commensurate with how soggy the gelatin is underfoot… so to speak.
Having gone through this amount of stress simply to get ink onto the plate, the printer then needs to take care on whatever press is available, providing sufficient pressure to ‘bottom the paper’ without breaking the glass!
The current state of collotype is that it is loved, admired and cherished, but rarely undertaken by individual printmakers. Often the preserve of universities or historic organizations with access to the required plant; collotype printers are a mutually supportive bunch. A recent collotype conference at the University of the West of England in Bristol gave encouragement by bringing together both active and interested printers from the USA, the UK, Germany, Italy, the Netherlands and Scandinavia.
Where no alternative inks are available, lithographic inks act as a first reserve, however they are commonly too weak and too soft. A genuine collotype ink has greatly increased pigment content and as a consequence is of far higher viscosity. It is our understanding that a sizeable proportion of Caligo Collotype Inks may not in fact be used by collotype printers, but by lithographers and other printmakers who simply want to experiment or use a very viscous ink!
Collotype is a temperamental process requiring great patience and skill. Results appear to differ dependent on temperature, humidity, the number of Thursdays in the month and the price of fish in Lapland.
Even a collotype enthusiast admitted that ‘it is hard work considering sometimes you get a print and maybe sometimes you don’t’!