Converting US and
Asian / European Stock Weights

We measure paper weight in pounds (lb) and points (pt) in the US. Asia and Europe measure in millimeters (mm) and grams per square meter (gsm). If you have questions you can contact us at (425) 603-1777, or by email through from our Contact page. Standards vary from country to country, but the charts below will give you some of the possible conversions. We may alter specifications on a quote if we find a better cost in a different country than used in these charts. Example: If you  currently print on 60 lb offset, you can go to either a lower weight, 80 gsm wood free (uncoated paper), or a little heavier weight, 100 gsm.

Coated stock — Gloss Art or Matte Art for coffee table books

• 54 lb = 80 gsm
• 61 lb = 90 gsm
• 68 lb = 100 gsm
• 82 lb = 120 gsm
• 101 lb = 150 gsm
• 122 lb = 180 gsm
• 135 lb = 200 gsm

Uncoated stock — Wood Free (offset) novels, children’s books

• 54 lb = 80 gsm
• 68 lb = 100 gsm
• 81 lb = 120 gsm
• 95 lb = 140 gsm
• 122 lb = 180 gsm
• 16 pt = 360 gsm

Perfect Bound cover stock — art board; C1S, C2S, gloss art, matte art, and wood free

• 10 pt = 200 gsm
• 12 pt = 250 gsm
• 14 pt = 300 gsm
• 16 pt = 350 gsm
• 18 pt = 400 gsm

Hardcover binding board — Grey Board for hardcover books

• 60 pt = 16 oz. = 1.4 mm = 1,000 gsm
• 65 pt = 20 oz. = 1.8 mm = 1,300 gsm
• 70 pt = 24 oz. = 2.0 mm = 1,400 gsm
• 80 pt = 28 oz. = 2.2 mm = 1,600 gsm
• 88 pt = 32 oz. = 2.6 mm = 1,800 gsm
• 92 pt = 36 oz. = 2.8 mm = 2,000 gsm
• 98 pt = 40 oz. = 3.0 mm = 2,100 gsm
• 140 pt = 48 oz. = 3.4 mm = 2,400 gsm

PPI (Page Per Inch) counts determine spine width

Spine width is important so that the graphic designer knows what size to make the title on the spine. Star Print Brokers will provide a template with the measurements and spine width for dust jacket, cover, and/or cover wrap. Paper conversion is used to determine the paper thickness. We can then calculate the width of the spine.

Example Formulas:

Soft Cover

Divide the page count by the PPI noted in the charts below. Add 0.03″ to allow for gathered signatures, cover and glue. Example for 184 page book printed on 140 gsm matte art: 184 pages divided by 348 ppi equals 0.53″ plus 0.03″ equals a spine width of 0.56″.

Hardcover

Add thickness of front and back boards. Gloss is thinner than the same weight of matte.

Matte Art — (Coated)

• 80 gsm = 651 ppi
• 100 gsm = 546 ppi
• 120 gsm = 454 ppi
• 140 gsm = 348 ppi
• 180 gsm = 282 ppi

Gloss Art — (Coated)

• 80 gsm = 726 ppi
• 100 gsm = 605 ppi
• 120 gsm = 535 ppi
• 140 gsm = 405 ppi
• 180 gsm = 332 ppi

Wood Free — (Uncoated)

• 80 gsm = 552 ppi
• 100 gsm = 462 ppi
• 120 gsm = 552 ppi
• 140 gsm = 552 ppi
• 180 gsm = 552 ppi

Contact Star Print Brokers for Information or Quote Contact Us