I have been using SMG for a few months and they are great people to deal with. After receiving my last order of text in red and gold I found they wouldn't transfer correctly to dark shirts. I talked to SMG and found out they use two different thickness screens. The thinner one is for printing that will go on light colors and the thicker one is for darks. Earlier that day I used calipers to measure the thickness noticed there is a difference. The ink thickness for lights and darks are about .00025 and .00050 respectively. They used the thin screens by mistake. This is the first I have heard of two thicknesses being used. If you are going to be using a color for light and dark shirts be sure to remind them to use the thicker screen. They are reprinting the order correctly.