Rookies at WB/DC here and spoiled a 60 shirt job job today. Need some advise in prep for the reprint. 1c WB gray on a Dark Heather Canvas 3001cvc (52/48 cotton/poly). Folded them in half on the dryer with sleeves in and they shifted darker towards a brown hue, top-side, permanently. Once laid flat, the scorch was very apparent. The tags were not crispy. Curiously, some of the first shirts on the belt, laid flat shifted completely, shifted both sides, top and bottom evenly. All sizes shifted so they may rule out a dye lot problem. Maybe just too hot, too long for a heather, or are heathers just scary shirts to WB? However, we did this same shirt WB last month in heather blue and no color shift. Humm.
Sprint 3000 with 8 ft or heat
Original spoiled run, 355 degrees at 2.5 min
2nd test run, laid flat to scorch the rest of the shirt, 325 for 1.5 min. (shifted, but not quite as much)
3rd test run, laid flat to scorch the rest of the shirt, 355 for 1.5 min (same scorch level as original)
What temp and time would be a good starting point to run some cure and wash tests?
Thanks in advance for the pointers.