I started screen printing multicolored art on transfer sheets. Being that my vacuum platen is made from lexan, I cannot use the print - flash -print method. I print each color individuallythen run the paper through the dryer and place the paper back on the platen for the following color. I fastened a small framing square atop the platen so I can butt the corner of each sheet of paper up to the inside corner of the framing square. I still cannot get precise registration from sheet to sheet. I average about 10 good prints out of 14. Any suggestions?