Sample Preparation Hint
One of the most common mistakes in sample preparation is trying to cut too wide a surface with the razor blade. End grain is very hard and, the more wood in contact with the blade edge at a given time, the harder it is to cut. Since you only need a surface about 1/8” wide to observe growth ring features, that is all the wider your sample needs to be. So, use a sharp knife to chamfer the edges before you cut the final surface with a razor blade. If the end-grain surface of your sample piece is very wide, use a fine-toothed saw or triangular file to place a notch near one edge.