I have been running some “Introduction to 3D Printing” talks for the staff of our local libraries because there is the potential that 3D Printers may be introduced there to help with growing the local technical awareness. To this end the Library has been gifted a Makerbot Replicator 2 by Ricoh. For my talk I was keen to print something relevant to the library staff that would print within half an hour. I searched Thingiverse for ages and found some really cool stuff but nothing that was going to be able to print within the time limit. Luckily inspiration struck. I would create a “Like” thing that the library staff could put between books on a shelf to indicate the “Staff Choice of the Week” or something like that . During the talks people pointed out to me that it could also be used to indicate “Worst Book of the Week” by turning it upside down – so even more versatile than first envisaged! I guess it is a little unclear which book on either side of it is the one being “Liked” but maybe its both or even the whole shelf. The design of the thumbs up thing took no more than about 10 minutes in Inkscape, and then extruded in Blender within another five or six minutes. Printing on the Makerbot with settings similar to the standard “Medium” settings took about 27 minutes to print and 6g of filament. The Exclamation Mark and Star indicators were suggested to me as alternatives that can sit above the books to avoid problems with the indicators falling out of their slot between the books. Again these two take between 20 and 28 minutes to print. Adding shop or library names would be an easy modification but would be likely to extend the print time by quite a bit. Anyway, fun to design, make, and use in the demonstrations.It's pretty simple. These were printed at 15% fill density which makes them pretty strong. The Blender and SVG files are included in the downloadable files so you can customise them as you like.