This is probably the biggest problem for people who are changing over to water-based inks, particularly from plastisols, which are very forgiving in this regard. 

Prevention is better than cure, so a good first step is to keep humidity in the print area above 40-50% RH. Once the relative humidity gets below 40%, the inks will show much greater propensity to dry in and printing will become a lot more difficult. Getting an hygrometer for your print room is a great investment.

When printers first start using water based inks, they can spray a fine mist of water every 15-20 prints to maintain the moisture of the ink on the screen. Some printers swear by this method. The most important thing is to flood the screen with a layer of ink (1-2 mm; 1/16-1/10”) and to keep the ink moving; that is, work quickly (but don’t rush). If a screen has been sitting around doing nothing for a while, pull a test print from it onto a scrap T-shirt, piece of fabric or even newsprint and inspect the clarity of the print, particularly around any fine detail.

If the ink does start to dry on the screen a little, don’t panic. Just pull another print on a test piece, so that as much ink is cleared from the image area of the mesh as possible, take a damp rag and clean both sides of the screen, then remove excess moisture with another rag. Reflood the screen, take another test print and then you’re good to go again.

Mesh count is often a factor. Most garment printers use a 43T (110 tpi) mesh. All other things being equal, the higher the mesh count, the quicker the ink will dry in. However, S-meshes have been a wonderful invention for printing with water based inks. With S-meshes, higher mesh counts can be more forgiving than the same thread count with a conventional mesh. Check out the S-mesh comparison tables.

Use a good emulsion that is compatible with water-based inks and maintains its integrity and you can get good results even with a coarser mesh. With increased experience, you will eventually master 77-90T (195-225 tpi) meshes for SUPERCOVER and up to 120 T (305 tpi) for PERMASET AQUA, PERMATONE and PERMAPRINT Premium.