There are multiple ways of denoting the caliper (thickness) of a paper, and there are also multiple types of papers with identical calipers but different characteristics.
|Standard Paper Caliper & Equivalent Conversions:|
Each row of the above chart represents a single caliper of paper (eg. 16 lb bond is identical to 40lb text paper in thickness). In the US, the most common way of denoting caliper is with Bond. Generally, thicker paper has less ink show-through and bleedthrough, but equivalent caliper papers may have very different opacities.
Vela uses a high opacity (95% opacity) paper that minimizes ink show-though and bleedthrough with most pens.