Problem:Part or all of image on plate does not take ink.

Plate Blinding - Chemical

Cause:

1. Fountain solution too acidic
2. Excessive gum in fountain solution
3. Plate cleaners and/or scratch removers have dried on plate image
4. Fountain system contaminated by detergent
5. Excessive fountain solution in ink
6. Improperly developed plates; gum adheres to image area

Solution:

1. Adjust fountain solution to proper pH/conductivity (pH 4.0-4.5)
2. Re-etch plates and rub up image areas with press ink; replace fountain solution with tap water; if image returns, replace tap water with fountain solution containing less gum
3. Rinse plate well after cleaning
4. Thoroughly rinse all washed parts before re-installing in press
5. Reduce dampener setting to minimum level; consult ink manufacturer Wash plate thoroughly; remake if necessary

plate blinding or wear