We build our all of our HDU signs in our studio and workshop in Murrieta, California.We start with 4 ft x 8 ft or 5 ft x 10 ft sheets of High Density Urethane (HDU) that are 1.5 inches to 2 inches thick, depending on sign size. We first cut the big sheet into sign-size blanks with our large CNC router (5 x 10 ft table) to get the outline of the sign shape. We the remove material with our CNC router to provide a 2.5D or 3D relief profile. For sandblasted signs, we then put the sandblast mask on areas of the carved sign we want to remain smooth(usually letters, borders, and art).

We place the sign with its mask into a large enclosed booth. . We may use a wire frame to produce a simulated wood grain pattern, or omit it and produce a sandstone texture pattern. We remove about 0.1 inch of HDU in the background. in addition to the 0.8 to 1 inch of material removed by the CNC router.

The edges is then routed to the style the client has selected. The edge is machine-sanded after routing and sandblasting has been completed.

After sand-carving, routing, machine sanding, hand-carving and hand fine hand-sanding (to 300 grit) have been completed, the sign is cleaned with high-pressure air and a colored epoxy resin is used to coat the entire sign. This is specially smooths the surface , provides additional surface hardness, as well as providing a high adherence base for oil or acrylic paints.After the prime coat has dried, all letters, numbers, borders , and Silhouette Art icons are hand-sanded with 300 grit and then 600 grit sandpaper, to provide a smooth finish. We then apply two coats of MNathews polyurethane paint, 1-SHOT oil enamels or Sherwin-Williams acrylic outdoor paint over the entire sign, except the back side, which has one coat.
The paint is applied to the background, borders, letters, numbers and Silhouette Art with an airbrush or miniature roller. The 1-SHOT enamel is applied to the CarvedArt with artist brushes.After the first coat, all letters, numbers, borders, and Silhouette Art icons are hand-sanded with 300 grit and then 600 grit sandpaper, to provide a very smooth final finish.

Depending on the content of the scene and the paints used,the CarvedArt icon may be given a final coat of two part automotive type polyurerhane clearcoat. .

The sign is inspected and allowed to dry two full days. It is then packaged and shipped.