I have sewn thru it and it isn't fun. It does gum up the needle but didn't hurt the machine, as others have mentioned there were skipped stitches. If your t shirts have large vinyl decals also it may be a bad combination. The vinyl is hard to sew thru also. It was also stiff.

Besides possibly gumming up the needle, I think it would make the quilt stiffer than you want in a t-shirt quilt. I use a very light weight fusible for them. Seems like it is Pellon Feather weight 911. It's been a while since I made one. Sounds like you may need to look somewhere other than your LQS, unfortunately.

Oh my! You people have me in tears, you are so wonderful. I am certainly going to take it back and read them the directions on the packaging. Luckily it's only 3 miles from my house.

Don't use Heat 'n Bond - use a very light fusible non-woven interfacing. I've made several t-shirt quilts using that and had no problem. And they are so soft...

Do not use the heat and bond! For t-shirt quilts I use Pellon 911. Very easy to use and remember.

So what does a person use Heat'n'Bond for? I'm not familiar with this product.

I use non woven fusible interfacing-lite weight. Take that stiff stuff back to store and tell whomever it was that told you that to please re-educate themselves!

https://leahday.com/products/french-fuse

i saw Nancy Zieman use this too

Misty Fuse is a good one to use and doesn't make the item stiff.

I also use a light weight knit iron on interfacing for t-shirt quilts. It quilted just fine with invisible thread no less.