I have a couple (10-ish? maybe) tshirts that dont fit anymore. They all have nice prints on the front that Im plan on keep, I can always make a quilt, I think.
But what to do with the back of the shirt? Its about 40 cm X 50 cm more or less. Or should I just donate the whole thing? Some of the shirts is just worn once or twice, so I dont have that much of nostalgia or memories with them.
When I make a tshirt blanket I use both sides, rotating one of them so the stretch is going side-to-side on one & top-to-bottom on the other. It’s not a quilt but it makes a really nice blanket for snuggling up to watch tv, or a beach blanket. Very easy to wash.
Yeah, that was my thought on using the front, a blanket. So might have used the wrong word with “quilt”. But using both sides sounds smart. Thanks for the advice @Magpie !
If you don’t have much nostalgia with them and think someone else would wear them, donating is a perfectly legitimate option! If you do decide to use just the fronts for something, tee shirt material really does make excellent (mostly) lint-free rags. Great for lots of general cleaning, but also for polishing, waxing, burnishing, etc.
That is a good advice! I hadnt thought about that! Need to look through them now and decide what to do! Thanks! 
I use t-shirts for rags too. They’re good for those messy jobs when you might want to toss the rag afterwards… Or, I end up washing them a couple times for less messy situations.
I’m a bit wary about donating t-shirts unless they are in great condition, or I can rehome it to someone I know wants it. If it’s not sellable on the local secondhand market it could get exported (sold) to less picky markets. End of the line might be a landfill in Ghana or in the sea if it’s not sellable there either. Sooo… rags it is.
T-shirt yarn is another fun option, but better for T- shirts where you don’t want to save the prints.
Things I do with t-shirts
Make t-shirt yarn it crochet, knits and weaves up nice into rugs and baskets/bags or chair pads and trivets
I use large pieces and make decorative burp cloths they are a nice solid piece for one side.
I cut off the collars, sometimes alter sleeves and hems and can add a crochet or tatted edging to change it up
I keep several of the backs for remodeling they are great for applying stains and oils where you’re going to properly dispose of that rag after.
Sew a few layers don’t even worry about the edges leave them raw, great wash clothes, cleaning rags etc
I braid them and tie really tight for dog tug of war toys for my heavy chewer!
@Annchen These ones are in sellable condition. I have a couple that are not, and they are in another pile.
And yes, you are right about going to a less picky market. Tbh, I dont know what our big second hand-chains do with the things they cant sell. Maybe I need to look that up. Maybe its better to make rags of them…
But the t-shirt yarn is a good idea!
@Bugaboo You have lots of ideas here! Thank you! Now I need to look through the shirts again and think of what to do!