How to repair wood furniture surface from chemical blemish?
Stain markers are mostly felt pens. You can buy a kit of various colors. Surf the web using 'Stain Markers' as a search term and you will find plenty of suppliers. There is some art to this as each stained wood color needs a very close match to look real. Some of these stains also partially dissolve the existing stain so they merge together. Go slow and do small sections first and check the results. Adjust colors for best match possible. Move the pen or brush in strokes with the grain of the wood, starting with the lightest colors first, then move toward the darkest color. Do NOT coat with a clear lacquer until you are satisfied with the results, because you will need to lacquer the entire surface for it to look right. Use a thick coat so you do not have to do it twice. Doing so can cause ripples in the lacquer.