Shappy 100 Pcs Hand Wrist Strap Lanyard Bulk 7inch Nylon String for USB Flash Drive Cell Phone Keychain ID Badge Holder(Black)

Love it! I was doing the same with a flat whistle design I got from Printables. I used BambuStudio to add lettering in the bottom 3 layers, and then just printed some Avery labels for the top side to keep the filament changes to a minimum. I used these lanyards: https://www.amazon.com/dp/B0F1TRMQCX?ref=ppx_yo2ov_dt_b_fed_asin_title&th=1