Boxes with corners of finger or dovetail joinery become more distinct when an oil and/or clear coat is applied to the wood as it darkens the end grain increasing the contrast with the regular surface. I'm a noob and I've been trying to find a means to achieve this for quite some time. One of the issues is that while I could assign a darkened version of a procedural material to faces representing the end grain of a part, there's no way to make it match the material being applied to the other sides.