I made this pattern and sewed these.
They hold bags of rice, which are microwaved to warmth.
The pockets act as insulation, and can be washed if the cold paws are also dirty ones.
Not a stitch is showing. Even the bottom of the liner is hand-stitched so the thread is hidden.
I made this, though I'm not entirely sure why. Inside is nothing but a 7-segment LED module. Unlit, of course.
And some food. Important too.
I gave the honeycomb sandwich another go, this time with some degree of success. Made with strips of corrugated cardboard.
Useful? Eh! I'll know how to make it when I need it, though.