A mesh backing is a wire net to which the tiles on a mosaic sheet are attached. Not only does it help give adhesive extra grip, but they allow a mosaic sheet to be cut in to any desired shape. This means you can turn 1 mosaic sheet into 3 or 4 borders and potentially save money!
The flexibility with mesh backed mosaics also allow for installation on curved walls/surfaces and because they can be easily cut, little goes to waste.
Cut from the back, create a straight line by folding the sheet, then simply cut by dragging a stanley knife down the the length of the curve.
Are all mosaics mesh backed?
The vast majority of mosaic come on a mesh backing.
How are mosaic tiles stuck to the mesh?
With a semi transparent adhesive.