Will these keep an 11 x 17 inch poster on a wall? Thank you.
We would not recommend these for hanging posters on walls. We would suggest using command hooks for posters.
Are they safe for skin and easy to get off?
Although they probably won't hurt skin, this is not something we would recommend as these are made for paper and card stock products.
Can these be put on an invitation and be pulled off easily without tearing the invitation or the attached card?
They are fairly sticky. We would say that they are a permanent adhesive, not a repositionable adhesive. Once you adhere them, to card stock, they will be difficult to remove.