I use pencils and watercolor pens. Postcard Signed HΛCHIZΛME (hz.) The back is plain white, so it can be used as a postcard. There may be slight differences in color between the image and the actual product. The lines may appear a little darker in the actual product. If you are at all concerned, please refrain from purchasing. We will take measures to prevent folding and water damage when shipping. Thank you for viewing.