Wood finishing is an inherently dangerous pursuit. Blotching Pine, cherry, birch and aspen are some of the more common species of wood that usually present a problem when trying to color or stain. Some apparently random areas on the surface of the wood drink up a whole lot more color, leaving dark blotches. The blotches do not relate to figure, or a wood feature like knots. Blotching seems to be proportionally worse when using a very dark dye or stain.
Blotches can really ruin the appearance of an otherwise nice finish.
Most of the workarounds presented below have shortcomings, mainly that all of them involve extra cost or extra effort. None are a complete guarantee against blotching, but they do represent a big step towards a great finish. No matter which of these you select, be sure to TEST the effect on scrap before you attack your project. You may need to use more than one method to get premium results. Washcoating Washcoating means applying a low solids film to raw wood before any coloring steps.