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If you want "no seams" then you don't want tiles, period. That's what sheet vinyl flooring (often still misnomered as linoleum, though actual linoleum is quite, quite rare these days) is good for, if the space to be covered is less than 12 feet in one dimension (after that, you're stuck with a seam.) It actually has no seams (if the 12 foot limit is not exceeded - 12 by whatever is fine, as it comes on a long roll, 12 feet wide.)
I have self-stick tile in several spaces - basically low-traffic closets, and it seems fine in those on its own adhesive, applied with care to a very carefully cleaned floor. If you are breaking out the tile adhesive, might as well break out the commercial-grade vinyl tile (made with no stickum) it's made to go with, which is a far better tile at not much more cost. The difference should be obvious comparing the two types - HD typically carries one, perhaps two colors of commercial vinyl (all the others are "order and they'll get it"), and it's a much thicker, more solid vinyl than the thin stick-ons. It's basically all wear surface until you wear right through it, while the stick-on starts thinner and has a much thinner wear layer.
A third possibility is an epoxy coating, with or without "color chips."
I have seen self stick tile not lasting as long as it should. Tile with adhesive is the way to go if you want durability.
Title basically. Wife got these tiles for the basement but after she laid them, most don’t really stick. What should we use to keep them down?