Positive Litho Plates
Emerald Plate
Emerald positive working litho plate is a .012" thick ultraviolet light sensitive plate used for photolithography. Emerald plate offers great performance and exceptional cost savings.
Exposure
Exposed with a single point U. V. light source, this photo sensitive litho plate gives direct results for positive photographic or hand drawn film. Test strips should be exposed using the original film transparency, and a 21 step scale. Expose to achieve a solid 4 of 21.
Developing
For best results Emerald positive working litho plates should be developed using a rocking motion in a printmaking tray with positive plate developer powder. Agitating the emulsion on the surface of the positive litho plate with a developer application pad is beneficial, especially during large plate developing.
Image area Deletions and Additions
Deletions can be made with image remover pens, or deletion fluid. Additions can be made with image addition pens.
Printing
The plate is ready to print after a layer of positive plate FPC (finisher, Preserver, Cleaner) is applied to the plate with a sponge, then tightly buffed in with cheesecloth.
Storage
Remove ink from the plate with lithotine, then water. Fan dry and apply a layer of FPC (finisher, Preserver, Cleaner), to the photolitho plate with a sponge, then tightly buff in with cheesecloth before storage. Store positive litho plates so that they are not exposed to U. V light.
Reference Material
The Tamarind Institute has published a manual on photolithography, which contains detailed information on positive plate lithography, as well as negative plate, and photolithography from stone.
Emerald Plate
Stock plate sizes and pack quantities
- 19 5/16" x 26 1/2" x .012" (491mm x 673mm) packs of 10, 20, 30 and 50
- 25 1/2" x 36" x .012" (648mm x 724mm) packs of 10, 20, 30 and 50
- 30 5/16" x 40 9/16" x .012" (770mm x 1030mm) packs of 10, 20 and 30
- 32 3/8" x 42" x .012" (822mm x 1067mm) packs of 10, 20 and 30
- 40 3/4" x 50" x .012" (1035mm x 1270mm) packs of 30
- 36" x 52" x .012" (914.4 mm x 1320.8 mm) packs of 30
Chemistry
Positive Plate Developer Powder is mixed with water and used to develop photo litho plates. 4 oz. bag mixes with one gallon of water.
Positive Litho Developer Application Pad is used develop photo litho plate. Apply developer to positive litho plates with this soft micro fiber pad the gently agitates and removes emulsion without scratching.
FPC (Finisher, Preserver, Cleaner) replaces aqua image finisher preserver cleaner. For use on Emerald Positive Working Litho Plates.
Kodak 231Deletion fluid is a liquid form of image remover Works on photo litho plates as well as ball grained litho plates. Also works well on litho stone.
250 ml / 8.45 oz. Bottle
Supplies
21 Step Scale is a standard test strip, used to evaluate variables in exposure of photo sensitive plates. Note: expose Emerald positive working litho plates to achieve a solid 4.