A rubber stamp to tel people to “Keep circulating the books!”.
I donate book that i’v read to the public bookcase near my house, but i don’t want these books to show up as merchandize of a for-profit second hand book seller.¹ Books i put into that bookcase are to be free!
So, to deter people from selling these, or rather from paying for them, i stamp my used books with this.²
The actual “rubber” part, the bottom 2 mm, should be done with soft, flexible material, at least fPLA or something like filaflex, and change to standard PLA then.
This was done with OpenScad. One trick i used was
hull(), to get the plate and spars with exactly the size and shape of the text.
I have made two more stamps, that you can get from github repo. There is some design history available there, too.
I use “Simplified Spelling Board”/“Handbook of Simplified Spelling” rules.
¹I hav no idea how common this is, or if it happens at all.
²I hav no idea how effective this is, either.