The sets are "woven" from individual threads. This means that the surface is not 100% closed and liquids can partially pass through the mesh on the table. Those looking for placemats that reliably protect the substrate from contamination (eg for use with infants), will be disappointed.
For normal home use, however, I can absolutely recommend, because they also have the advantage in addition to a really beautiful look that they are easy to clean, but if times bib the placemats.