I love that 3L has combined both the small and large foam squares in one package. These squares stick very well, even for altered projects. The black squares are practically invisible on layouts and projects as well. They are also easy to peel from the sheets since the "negative" part of the package has been removed and only the squares remain. These rival glue dots as a go-to adhesive in my stash.
I have used the white squares and found them to be effective in creating depth to a card. Until I saw these, I had been taking a color ink marker and coloring the edges of the white to make them less noticeable. With this squares, I don't have to do that.