Tips for Screen Printing with Water-Based Inks

Joe Clarke has spent the past 47 years in the lab and in the engineering department, in pre-press and on-press, as an R&D / technical researcher and as a manager of screen print production. Clarke has held executive positions as President of M&R Printing Equipment and as Vice-President at Wilflex [Poly One]. He has been granted a growing number of print-related patents, including one for High-Shear printing with Smilin'Jack - he is a member of the ASDPT, is an Associate Editor for NBM and an SGIA Fellow.

Clarke has presented hundreds of technical papers, written a couple books and published over 600 technical / management articles for which he has been awarded five Swormstedts; the international standard for excellence in technical writing.

Currently Joe Clarke is the President of CPR, a Chicago-based corporation which manufactures Synergy Inks including NexGen; environmentally & financially responsible T-Shirt inks. For more information on CPR, visit http://www.cprknowsjack.com/.

Unlike printing plastisol, where the objective is to lay ink on the substrate surface, water-based inks need to actually be driven into the substrate. To do so, it’s necessary to maximize the pressure between the squeegee blade and the mesh, then flood and print at maximum stroke speed.

To achieve this goal, start with a thin-thread, low-count screen mesh and use a fill stroke at maximum speed to pre-load the cells of the mesh with ink. Then use a sharp edge, single-beveled blade (bi-axial preferred) that will print at moderate pressure and maximum stroke speed without buckling.

The key is to increase the off-contact gap in about 25 percent increments until we are compressing the T-shirt without deflecting the platen.

If the ink allows it, the penetration will be superb. If not, gingerly add a reducer. If the ink penetrates through the garment and onto the platen, decrease blade pressure by about 25 percent. If there is still residual on the platen, increase the off-contact gap by about 25 percent and repeat both steps in order as needed.