These letters are designed with finger tab holes to be cut onto scrap pieces of wood. Start with two thin pieces of wood the same size (or cut them with your laser). Then drop the letters you need into your cutting app (like Glowforge) and cut the top layer with the letters. Then glue the negative of that cut to the other piece with wood glue and wait for it to dry. Once dry paint the base with a light color and the letters with a dark color (or the other way round).