Chasing a problem on a high speed Lithoman IV. At higher speeds the Black will start to print unevenly. Strange, it seems to happen only in small solid subject areas. Text type, 10 pt will print fine and then 48 pt Bold type will be distorted. Have run the gamut of changing inks. More water pick up, less water pick up, more lubrication, more stability, no help. Happens at higer speeds; 30,000 x 2, over 2200 feet per minute. Slowing the press down, alliviates and helps the solid black return to continuity. Have used 2 Fogra type fountain solutions at 4.5 - 5.0 and also normal acid solution at 3.8 - 4.2. Conductivity normally 2000 uhmo. Use FUJI LH-PJ plates and Day 3610 blankets. Happens on 70# Gloss and also some lesser weigt sheets. 45# Escanaba usually runs OK. Automatic blanket washers, using a Green Varn product. Halftones OK, text type, all oK. Small solids black again the problem. Sometimes magenta, but may be different problem. Only occurs about 15% of total press running time. Don't think it is an ink problem. Looking for suggestions. Help!!!!!!!!!!
