The amount of ink you print will vary on setup and affect color. So a 60 duro narrow squeegee will lay down more ink than a 70 duro wide squeegee. So this is just subjective viewing and adjust duro, angle, speed, pressure until it matches previous prints, and it isn't easy. The amount of ink in the screen and how frequently you add ink also can affect how it discharges. We tried to keep at least an inch of ink in front of the squeegee at all times by building ink dams around squeegee/flood stroke to keep it localized and added a drop of activated ink every 10 prints or so with a worker walking the back of the press. (We did 7-10 color discharge prints.) Keeping ink fresh every couple of minutes helps. Then there is shirt fiber. It tends to gather in the center of the print path and needs to be removed and scooped out. About 4 hours of printing and you could see a dip in the bead of discharge ink that would print a dark stripe down the middle of that print.
Then to make it more interesting, you need to measure out activator and base precisely and keep that ratio consistent. I used small plastic cups pre-weighed for a quart only and added to exactly 1 quart of base. Then there are dye lots in the shirts. One dye lot may discharge a bit different than another even though they are the same color shirts. this is why we liked adding pigments to the base. You can duplicate the greige goods color with pigments and print a tan far easier. Then the difference in squeegees, print speeds, is not as crucial since the pigment is left over and shading isn's as noticeable.
