Scumming - Ink adheres to non-image area of the plate during the press run and cannot be removed using a damp sponge.

Ink emulsifying
Running too heavy of an ink film
Lower ink setting. Switch to stronger pigmented ink to achieve desired density with thinner film.
Fountain solution too Alkaline
Increase amount of concentrate, or switch to more acidic solution.
Conductivity is too low
Remix solution.
Plate surface has become sensitized
Use a good plate cleaner / desensitizer.
Too much reducer added to ink
Replace ink.
Fountain solution contains too little gum
Remix solution using more gum, or if using a one-step solution, use more concentrate.
Excessive use of alcohol substitute
Remix solution using less substitute.
Burnishine recommends using our fountain solutions to combat this issue: Universal Fountain Solution, Universal SM Fountain Solution, Universal Fountain Solution - SM Plus, Ultrafount Fountain Solution, as well as our plate cleaners: Plate Sav-UR, Aqua Blue, Plate Care and Gold Miracle