SheriR, that is wonderful!!!! Ditto on the proud of you.
Microfiber? Uh, domestic machine quilting? That will be a great challenge. Cotton fabric will work the same, expecially if you stabilized all the tshirts. I don't use sheets for the backs of my quilts, very difficult to quilt thru, even on the longarm, stitches don't always secure easily. Polar fleece maybe, but if they are cotton tshirts, cotton backing works very well. Just my opinion. I know, keep customer happy. I've made a few of those tshirt quilts and used cottong flannel for back. Worked well.
Dublb, nice selection of blocks, keep up the good work. Just think, you are a third of the way done!
I did finish the top of the cancer quilt. Thanks Fraew for the setting arrangement block. I did do that one, but had to end up making my blocks 16", which was good anyway because it gave me a better secondary pattern with the cornerstones. Will post a photo when I get there, clumsy me, fell, bruised self up and set back into overload again. Still finished that top. Now to pick some backing and get it quilted.