Printers have a bad habit of forgetting to heat their pallets before starting a print run.  The underbase does not gel sufficiently and ink sticks to the back of the subsequent screens, chaos ensues.  Start wiping screens.  The result is that the first half dozen or more prints lack opacity and are grossly undersaturated, enough so that they are deemed as misprints.  “But it’s only 6 pieces out of a 1000” says printer, “yeah, but it’s 6 of the 12 size smalls on the order” says you (tip: never start your print run on the garment size of lowest quantity).  We’ve all been there, but one thing is for certain, this is not a mistake.  The misprints were totally avoidable.  Pre-heating pallets should be standard procedure, a good habit that is as natural as breathing to any printer.  I don’t claim to have a fool-proof solution for instantly developing good habits in printers.  For some it just takes time.  Others may never learn.  But it is worth discussing with your printers, as a group, and explaining the difference between legitimate mis-prints caused by, say, screens breaking on press, and totally avoidable misprints caused by operator error.