A thimble is a metal cap with a closed end used in sewing to help push in the needle while protecting the finger. It’s simple, utilitarian, and ubiquitous, which makes it perfect for spellcraft.
My grandmother was a talented seamstress who liked to collect decorative thimbles from the different places she visited. I have a few beautiful ones on my altar to remind me of her and to act as a connection to those places. But they’re also useful for tapping into protective qualities.
On a strip of paper that can fit snugly inside the thimble, write down what you wish to protect. Roll up the paper and insert it inside of the thimble so it can’t easily slide out. If you want to make sure the paper can’t be read, thread a bead or small button on some red thread, then tuck it up inside. Place the thimble on your altar (open side facing down) or a similar safe place where it won’t be disturbed.