99% of Walltalkers products are applied over primed drywall, level 5 finish is recommended. Level 5 is the highest quality finish providing a uniform surface while minimizing telegraphing of seams/joints and fasteners.
Walltalkers can be applied over most clean, smooth, dry finishes, just like wallcovering. Resurfacing chalkboards and applying over steel are our second and third most popular types of installations. When going over steel, first see if the installer can use pressure-sensitive adhesive-backed products. Electro-galvanized, galvanealed, or "Paintlock" steel are recommended for applications requiring steel backing. Unlike regular galvanized steel, these do not have a dipped coating, so surface is smooth and will not chip when sheared. The matte finish allows a better bond to the steel. It is recommended to use a rust-inhibiting primer on the steel surface to prevent degradation/oxidation.
Applying wallcovering to steel is similar to going over glass. First, there must be a rust-inhibiting primer on the steel. Then, a wallcovering primer/sealer needs to be applied. Do not use latex primers, since the adhesive will remain wet for a long time, and this could loosen the primer. Primers made for difficult-to-bond-to surfaces will work best. Most adhesives are no longer made to work over oil-based primers. The installer will need to use a primer such as PROFESSIONAL R-35 over the base primer before pasting. Vinyl-over-vinyl or low-water-content pastes will work best, since the adhesive will be drying between two impervious surfaces.
Chalkboards can be resurfaced with wallcovering or pressure-sensitive adhesive (PSA). Follow PSA directions for installation. For wallcovering, determine what type of chalkboard you are covering. For painted hardboard chalk or slate surfaces, the surface can be cleaned, dried, and applied directly to the surface. Porcelain chalkboards may require some type of adhesive promoting primer, since these are impervious surfaces.
Any seams in chalk or steel surfaces should be filled or they will telegraph through the Walltalkers surface. Seam should be thoroughly cleaned prior to filling. Vinyl Spackle or auto body filler can be used to fill the seams. Either filler will need to be primed with a paint similar in color to the chalkboard surface; spray enamels work well.
Particleboard and hardboard can also be covered. When applying to these surfaces, they will need to be primed on both sides to prevent warping. The surface will need to be smooth so that imperfections in the sheet do not telegraph through the Walltalkers surface. Paneling, textured surfaces, and plywood are not recommended for resurfacing.