Originally Posted by
Prism99
Dryer heat is typically not enough to permanently set dyes these days. Most dyes require chemicals to set. Most likely the dye from the backing fabric came from over-saturation, meaning there were excess dye particles in the fabric. Fabric fibers can absorb only so much dye. When the manufacturer does not thoroughly rinse out excess dye, you get the excess dye in your wash. However, dryer heat is usually not enough to set it so Synthrapol still works.
I agree. Unless you dried it on High heat for a long period of time (and maybe not even then), there's still a decent chance the Synthropol will help. I'm not as familiar with synthetic fibers like fleece, but the white on your top looks like cotton so there should still be a good chance of getting the excess dye out.
Heat will remove dye long before it will set it. Temperatures higher than 140F (60C) have been known to pull out fiber reactive dyes. However, to actually permanently heat set dyes on cotton, you typically would need a temperature around 300F (150C). Domestic Clothes Dryers have been known to get to that temperature, but to do so, you would need to run the dryer with completely dry items inside of it for a good length of time. Speaking from experience, my mom's laundry strategy has achieved that. Here's what she does:
Step 1. Guess how long the clothes need to dry at the recommended dryer setting & set the timer for that amount.
Step 2. When the timer goes off, check to see if clothes/quilts are dry.
Step 3. If still slightly damp, change the dryer setting to High & set timer for maximum length of time (90 minutes).
Trust me, short of boiling water, there is nothing that is getting that dye spot out... and the boiling water could end up pulling dye out of your other fabrics, or pulling more dye out of the fleece.
Even though I break the "laundry rules" for college students because I know they are likely to over-fill machines, and dry everything on high heat, I still make sure to check the dryer every 10 minutes when it's nearly dry so it doesn't overheat. As long as you aren't leaving the quilt in a running dryer on high for more than 10-15 minutes after it's completely dry, you shouldn't have to worry about heat setting the dye spot (note: this does not apply to people who have dryers built before 2000; 15+ years ago, US dryer manufacturers lowered the temperature for the highest setting on household dryers).
By the way, it's a fantastic quilt! I really love the quilting & the piecing is great, too!