Paper weight conversion, size reference, grain direction testing, and OBA guide — everything in one place.
| Application | GSM Range | US Equivalent | Category |
|---|---|---|---|
| Copy / Office Paper | 75-90 | 20-24 lb Bond | Office |
| Letterhead / Stationery | 90-120 | 24-32 lb Bond | Office |
| Magazine Pages | 100-150 | 70-100 lb Text | |
| Photo Paper (Everyday) | 180-220 | — | Photo |
| Fine Art Photo Paper | 240-330 | — | Fine Art |
| Business Cards | 300-400 | 100-130 lb Cover | Card |
| Postcards / Invitations | 250-350 | 90-130 lb Cover | Card |
| Canvas (Inkjet) | 340-400 | — | Fine Art |
Paper feeds more reliably through printers when fed against the grain (stiffer direction). Heavier stocks (200+ GSM) are more prone to jams when fed with the grain because the paper can't navigate curves in the paper path as easily.
Always fold parallel to the grain for clean, crisp results. Folding against the grain cracks fibers, producing rough, broken fold lines — especially visible on heavy stock above 200 GSM. Score first if you must fold against grain.
The grain should run parallel to the spine of any bound book or portfolio. Paper fibers expand and contract across the grain with humidity changes — wrong grain direction causes pages to cockle, resist turning, or stick out from the book edge.
Mounted prints can warp if grain direction conflicts with the mount board. For dry mounting, align the grain of the print with the grain of the board. For large-format prints in humid environments, cross-grain mounting reduces dimensional change.
No optical brighteners. Natural warm-white tone. Color-stable under all lighting conditions. Best for galleries, museums, and archival prints. ICC profiles remain accurate over time. What you see is what you get — permanently.
Minimal optical brighteners — slightly enhanced whites without extreme fluorescence. Acceptable for most professional use. Minor color shift between UV-rich and UV-poor lighting. Some archival certifications still achievable (100+ years with low OBA).
Heavy optical brightener content. Brilliant "whiter than white" appearance that degrades over months to years. Significant color shift between light sources (metamerism). ICC profiling challenges. Not recommended for archival or gallery work.
Shine a UV-A blacklight on your paper. OBA-treated papers glow brilliant blue-white. OBA-free papers appear dull and unchanged. Battery-operated blacklights cost a few dollars and instantly reveal what marketing language won't tell you.
1 lb Text = 1.48 GSM
1 lb Cover = 2.708 GSM
1 lb Bond = 3.76 GSM
1 point = 0.001 inches
1 inch = 25.4 mm
Everyday prints: 200-240 GSM RC (resin coated)
Professional prints: 260-310 GSM
Fine art / gallery: 280-330 GSM cotton rag
Canvas: 340-400 GSM poly/cotton
RC (Resin Coated): Polyethylene-coated paper core. Photo feel, instant dry, flat, water resistant. Not technically archival by museum standards.
Cotton Rag: 100% cotton fiber. True archival, acid-free, no lignin. The gold standard for fine art and museum work.
Alpha-cellulose: Refined wood pulp. Middle ground between RC and rag.
Glossy: Maximum color saturation, reflective surface
Lustre/Satin: Reduced glare, fingerprint resistant
Matte: No reflection, softer look, less saturation
Baryta: Barium sulfate coating mimics traditional darkroom paper feel