Sharpen all the pencils in an artist pencil set equally. Inconsistent sharpening can occasionally cause the hardness value to be slightly off.
Draw a line on the paint sample with the 9H pencil. This is the hardest pencil in a set of artist pencils. In most cases, the 9H pencil should scratch the surface of the paint when used on it. The pencil hardness rating for a paint not scratched by this pencil would be 9H.
Draw a line on the paint sample with each progressively softer pencil. Use the 8H, 7H, 6H, etc., until you have tested the H pencil. The pencil hardness for the paint is equal to the first pencil that draws a line on it without scratching the paint. The H pencil can still scratch softer paints.
Draw a line on the paint with the HB pencil. You need to move to the softer B pencils if the HB pencil scratches the paint.
Draw a line on the paint using the B pencils in ascending order until one of the pencils draws a line on the paint without scratching it. The pencil hardness is the first pencil that draws a line on the paint without scratching it. The softest paints should be 3B hardness.
Things You Will Need
- Artist pencil set
- Dry paint sample
- Harder paints are usually more resilient but more difficult to work with. This is only a general rule of thumb, not a hard and fast rule. In some situations, a softer paint might be a superior choice in terms of durability. Harder paints are more prone to cracking if used on objects that expand or contract, such as wood furniture, than softer paints.
- You cannot test the paint hardness if it is covered in a clear coat. This only gives the hardness of the clear coat. It is best to create a new paint sample to determine the hardness rather than sanding off the clear coat before attempting the test.