How to Prep Mosaic Surfaces

The art of the Mosaic goes back in history 4,000 years. From its humble beginnings as simple pieces of clay pressed into a background for decoration, to the 8th century BC artwork of the ancient Greeks who added color and pattern to the decoration, mosaic creation has been a relaxing form of decoration and art. Today, while most think of it as a "craft", mosaic artists work on and with a variety of mediums and bases, creating outstanding works of beauty. Anyone can create a simple mosaic, and one of the most important first steps is prepping the surface you wish to use. Here's just a few ways how.

Things You'll Need

  • Wood, plaster, glass, mirrors, metal - whatever you choose to use as a base for your project

  • sandpaper

  • Dust cloth

  • Primer for wood and metal

  • steel wool or scouring pad

Step 1

Prepping a wood surface:Using a piece of wood is probably one of the more popular bases for creating mosaic pieces. The wood should be more than 1/3 inch thick, as thinner wood may break under the weight of the tesserae. (Tesserae is the term for any piece of tile, glass, etc that is used to make a mosaic.)Take the sandpaper to your selected wood base and sand it smooth, removing any rough edges or splintered sections. Wipe down with dust cloth to remove any minute sawdust. Using primer paint, paint surface and edges to prevent wood from cracking or rotting. Once paint has dried - project can continue.

Step 2

Prepping a glass surface:Making a mosaic using a sheet of glass, glass bottle or lampshade can be a beautiful way to highlight your piece. Using glass as your tesserae can allow you to create visions of light and color that can be enjoyed best when held up to light. When creating this kind of project, make sure you use the proper adhesive. A specialized glass adhesive will dry clear and bond glass better than standard mosaic adhesive.Prepping a glass surface is easy, but must be done carefully. Taking a piece of steel wool or scouring pad, lightly go over the surface of the glass in a circular motion. You may need to do this several times, as you don't want to press so hard as to break the glass, but you do need to score the surface. Wipe down with dust cloth to remove and "sanded" glass particles from surface and begin your project.

Step 3

Prepping a metal base:Using an old metal table as a base for a mosaic table is a wonderful way of repurposing a piece you might have otherwise discarded. Great to use outdoors, metal bases are easily prepped and can handle any type of tesserae.Begin your prep by carefully examining the table for any signs of rust. Using steel wool, sand the piece, taking special care on any rusted areas, to remove any loose dirt or rust. Wipe down with dust cloth to remove residue. Spray paint entire piece with a rustoleum type paint, making sure to cover any rust affect areas. This will seal your piece and prevent any further rusting. After paint has dried, score the surface you will be using with the steel wool. This will help the adhesive to stick.

Step 4

Prepping an outdoor base:There's a wide variety of items that can be used as an outdoor base for a mosaic project. Treated wood or metal have already been mentioned here. Terracotta, plaster or cement are also possibilities. Whatever you choose to use must be strong enough and sturdy enough to handle the weight of the tesserae you will be using. Garden planters are an excellent example of the perfect base for a ceramic outdoor mosaic.These bases will tend not to need much prep work. Most terracotta pots and planters are already rough enough to handle a good bond with the adhesive. You might, however, want to seal the surfaces to prevent any chance of water getting into the base and creating a swelling effect. This is specially important in the north where a winter freeze could crack your project should any water get under your mosaic. Spray the surface area with a porcelain sealer, if necessary using the scouring pad to lightly score any glossy areas, and continue with your project.


Cover the area you will be working on with plastic sheeting to curtail any spills/mess. Wear old clothes or coveralls and rubber gloves when working on any mosaic project as adhesives are not water soluble.


Please be aware of safety issues when dealing with glass/tile. Proper safety glasses, gloves, etc should be used. Maintain proper ventilation when using paints and adhesives.