Are these placemats non-slip?

Yes. Each mat has a rubber backing, which grips the tabletop far better than an unbacked cloth mat. That is the main reason to pick these over plain fabric placemats.

Can I put hot dishes straight on them?

No. The surface is printed fabric, not silicone, so a hot pan or baking dish should go on a trivet. Warm plates are fine.

Wipe the fabric surface with a damp cloth and mild soap, then wipe the rubber backing too. They are not built for heavy soaking, and oily sauces should be blotted promptly to avoid staining.

What size plate do they fit?

At 14x12 inches they take a standard dinner plate with room for a fork and knife. They are bigger than many cloth mats, so they suit full place settings.

Do all four mats have the same print?

Yes. The set is four mats in the same autumn fallen-leaves fine-art design, so a table for four looks matched.

How do they compare with silicone placemats?

Silicone wins on heat resistance and full waterproofing. These win on look and grip, since the printed fabric reads warmer than a plain silicone sheet.