A collograph is a process which allows the artist to get very textured, tactile, almost sculptural results. It can give very varied imagery and is capable of being printed in large editions if well made. It is essentially a collage which has been sealed with a thin coating of shellac for durability and is then inked up and printed.
Plates are usually made from from stiff card or thin hardboard. Woodglue or PVA is used to stick objects onto the surface to make up the image. An endless variety of things can be used with almost any texture as long as they don’t stand more than about 2mm higher than the surface ot the plate. Any higher will cause difficulties at the printing stage. Wool, dried foliage, lace, textured wallpaper and fabrics are all examples of objects that can be used. Painterly marks can be made by applying modelling paste with a brush and working into it. Tile adhesive is a good substitute for this. When the plate is finished it must be allowed to dry thoroughly.
Next, a layer of shellac is applied over the entire plate with a brush. Button polish, French polish etc work well as they are shellac based. If the surface of the plate is porous, a couple of coats may be needed in areas which you want to wipe clean of ink while printing. The plate is left again to dry thoroughly.
Etching ink is used to ink up the plate. It is best applied with a brush over the entire plate to work it into all the recesses of the plate. A small paint roller is also ideal. Most the ink is now removed as with a drypoint. A cotton rag is best to do this though scrim may also be used. Every collograph is different and it takes practice and often several attempts to get a satisfactory print. You need to experiment with different ways of wiping and settle on one which works.
The plate is printed as before but more care must be taken with the printing press this time. Get help if you are unsure how to set the press up. The pressure will need to be loosened and thick blankets used to accommodate the textures and thicker plate. Sometimes it’s preferable to use foam rubber instead of blankets to protect the equipment. A very durable printing paper must be used as the paper will be stressed more than in other processes.