well! when I started to want to be a wee bit more precise about my pinhole boxes, and concentrated on the pinhole, it seemed that this, the quality and size of it seems to be the thing. I used a micrometre to measure my sewing needles and was amazed at how most of them were way too big! at least for the tins and boxes I have. But the ones measuring .026, and .028 ( in inches) seem to be the most useful.