i have an hp indigo 3050 printing on offset substrates from 100gsm to 300 gsm. i hope you can help me identify the culprit or the solution to reduce or eliminate picking or appearance of white dots on colored areas. this problem come and go despite a controlled room temperature and humidity, proper curing of the substrate and there are days that we encounter this and some other days we don't (with the same paper stocks). the thing is we can have a very good prinitng but in a little over 20 minutes after printing, the picking takes place. how can we overcome this picking problem?... help is requested and appreciated. thank you very much