a)readily available and relatively inexpensive
b)is sturdy enough to withstand younger (toddler) siblings, yet that won't damage things like walls and furniture.
Thank you so much!
Having grown up with that, my recommendations are to not label in your primary language and to make sure they know the phonics of the other language, if at all possible.
Because as soon as I could read English, when I'd glance at the cards (placed on their objects, with a picture of the object on top), I just read the English and rarely read the Spanish or French. And the Korean I especially didn't read because I wasn't familiar enough with the writing system.
Of course, I was also quite old when the labels finally went up. I think if they had been used as a way for my parents to be reminded of the words, it would've been more helpful.
Physically, the cards were 4x6, with a magazine picture glued to the top, words written beneath, and laminated. Stuck up with regular tape, which wasn't a good method.