Backers: Info and Ideas

Choosing a backer is very crucial to the success of your mosaic project. Being familiar with your choices in backers will help you achieve the desired result you want with your mosaic piece.

Backers, bases, substrates, all refer to the same thing – what you will mosaic on. Backers should be non-flexible surfaces so there is no bending which can pop tiles off. They should also be made with the right materials for the environment your mosaic will be in. Do not use materials that will decay when placed outdoors.

Porous bases like terra cotta pots, wood, MDF, etc., should be sealed. You can use a mix of white craft glue and water to seal them before you mosaic. If not sealed, you run a risk of your tiles popping off since the base will absorb the moisture from your adhesive and weaken the hold. Keep in mind that wood eventually will decay. I do not recommend using wood in any type of outdoor mosaic at all.

Backer boards (Skeewbackers), ceramic, stone, wedi board and cement bases are great for outdoor or wet areas as well. Cement backer board is another choice for outdoor projects, although it is very heavy and harder to cut. Always start with a clean surface and make sure your base will be able to support the weight of your tiles, adhesives and grout.

QuikStik Mosaic Mesh is a fiberglass mesh which is a great way to work on a project in your studio, off-site. You place it over your pattern, place your glass onto the sticky fiberglass mesh and then you can adhere it to your backer. It is ideal for large mosaics that may need to be cut into sections for transporting or installing. Be careful of the fiberglass as it can irritate your skin so gloves are advisable.

Styrofoam is another fun material to use as a base. You can sculpt it or buy it in shapes like a ball. I like to apply a thin layer of thinset and then while it's wet, cover it with fiberglass mesh to give the Styrofoam extra strength and durability. Then I use thinset to adhere my tesserae to it.

So try different backers; but consider all the variables in order to make the right backer decision.