Your Skeewbacker is a Good Choice!
The most common mosaic backer choice is wood. It is easy to find, it’s cheap (sometimes free), easy to cut into many shapes, it’s rigid, easy enough to install hanging systems, etc. So, what’s not to love about wood? A lot.
It has three properties that are destructive to mosaics. They are:
1 - Moisture transfer. So that it can grow, the structure of a tree is made to transfer moisture. When it is cut and milled, that property remains. So, wood used as a backer for a mosaic absorbs and releases water from the air (humidity) and other sources. As it absorbs water it expands and as it releases the moisture it contracts. Eventually, these cycles of expansion and contraction breaks down the adhesion and the grout. That facilitates greater moisture transfer and ultimately the release of tesserae from the backer.
2 - Thermal conductivity. Heat causes some materials to expand more than others (it is significant in wood) and conversely contract more when heat dissipates. Some have almost no response to heat, like polystyrene (the materials of your new Skeewbacker). Similar to moisture transfer, these cycles of expansion and contraction break down the adhesion and the grout and ultimately result in the release of the tesserae from the backer.
3 - Rot. Because wood is organic, it is susceptible to attack by fungi which digest the fibers that give wood its strength. Some fungi work when the wood is wet, others when it is dry. Thus, the terms wet rot and dry rot. Whichever type of rot, the result is decomposition of the backer, and ultimately the release of the tesserae from the backer.
Skeewbackers have no moisture transfer, almost no thermal conductivity properties, and they will not rot whether indoors or outdoors. There is no fiberglass. Their only known vulnerability is to solvent based chemicals like some paints (especially spray paint) and some adhesives. Avoid those whose contents contain words like solvent, ethyl, methyl, toluene, and acetone. E6000 is an example of an adhesive with solvents. Do not use it.
The ancient mosaicists made art that lasted for millennia. We think that modern mosaic art should be true to its durable heritage. Your Skeewbacker will last as long as your tesserae allowing your art to be enjoyed for ages. That’s why you made a great choice.
Thank you for using Skeewbackers for your mosaics. Get more Skeewbackers here!