There are several methods for adding a print to a wood surface. Découpage is a familiar technique where paper cutouts are glued to a surface. The surface is then sealed with layers of varnish. An alternative method can transfer the ink of the design to the wood. This allows the grain of the wood to show through and allows the surface to remain flat and smooth without numerous coats of thick varnish.
Scan your image into a computer. Reverse the image and print it out on unsized paper. Unsized paper has a soft finish. It has not had sizing applied to the surface to make it glossy. If the package of paper does not mention it has a "photo finish" or other special finish, it will be unsized. If a drop of water sinks directly into your paper it is likely unsized.
Apply a coat of white, hard varnish to the wood surface. Allow it to dry for six hours or overnight. Cut out the print, leaving a 1/4-inch margin around the edges. Apply water to the back with a sponge so the back is saturated, but the ink on the front is not distorted.
Place the paper print side up on a sheet of cling film. Brush a coat of transfer varnish onto the print, covering it completely. Apply the print to the wood surface, varnish side down. Transfer varnish is also called spirits of wine; it is used to transfer ink images to wood.
Place another sheet of paper over the wet print and smooth it down until every part of the printed paper is stuck to the wood.
Remove the paper and gently rub the back of the print with your fingers to rub off the paper pulp. Rub gently so you do not distort the print. You may have to apply more water to the paper. Rub until all the paper is gone.
Allow the wood to dry completely and apply another coat of varnish.
Work in a well-ventilated place.