It is a basis-weight field
The selected paper is 300 gsm, also described as 140lb in the retailer’s paper convention. GSM expresses mass per unit area. It is not a thickness measurement, a total pad weight or a claim that the pad contains 300grams of paper.
Do not infer behaviour from one number
Two papers with the same gsm can differ in fibre, sizing, texture and format. The site does not guarantee flatness, water tolerance or resistance to erasing because a page says 300 gsm. It has not measured thickness, performed a wash or tested buckling.
A purchasing distinction
If the order specifies 300 gsm hot-pressed 100%cotton paper, keep all those fields. Replacing it with another 300 gsm pad solely because the basis weight matches would lose surface and material information. A heavier package weight may include the cover, backing and packaging rather than more usable paper.
What to do next
Read the selected paper specification and actual supplied label. The calculator does not turn gsm into paint demand, sheet thickness or an inferred net pad mass. If an exact thickness or tolerance is essential, obtain a manufacturer specification rather than estimating it.
Sources & scope
Checked November 5, 2026. Manufacturer and retailer references support the specific statements. Dated displayed prices are not final checkout quotes, performance rankings or performance testing. This shopping reference does not replace the exact product label or retailer instructions. Current received labels and independent art-material/chemical/content/commerce review remain pending.
Keep reading
Does a twelve-sheet pad contain twenty-four usable sheets? ↗
How should I choose between Hot Pressed, Not and Rough listings? ↗