Hopefully these images will help you decide what works and what doesn't work for memory projects.
Sizing....
This is how I usually cut items for blankets. This is a 12.5x12.5" square quilting ruler. See how it fits the whole image without cutting into the arm pits? PERFECT!
Old Fashioned Jerseys
The good ol days when jerseys could breathe....but not really.
These do not work for any project.
Reversible Mesh
I can't use either part of this because of the size of the holes in the fabric.
Football Jersey
These do not work for any project. See how big those holes are? Only jerseys that work are Dri-Fit and solid.
Lovely chunky sweaters
No one in the universe has figured out how to make these work on repurpose projects yet. When they do, they should patent it.
Gramma's Cardigan Sweater Set
Even if the knitting is fine as frog hair, it isn't usable in a repurpose project.