The European measurement of describing paper weight measures a single paper with a two dimensional height and width of one square meter. This measurement is noted as g/m2 (gm/m2, gsm, g/m2). The measurement may be measuring a hypothetical square meter, but is a good "apples to apples" reference because it compares the weights of different size papers.
The English method of paper weight may be more familiar to people, but it has its drawbacks when comparing weights of different size paper. The English method of measurement gives the weight of the paper as if weighing 500 sheets (or a ream). Differences in the dimensions of paper are not taken into account. Therefore, the English weight of a letter size paper that is thick and dense may be the same as a poster size paper that is light and tissue thin because 500 sheets of each weight the same. It's the "which weights more, a ton of lead or a ton of feathers" quandary.
| English paper grade to grammage conversion | |
| Grammage | Paper Grade (LBS.) |
| 44 gsm | 30 lb. text |
| 59 gsm | 16 lb. bond, 40 lb. text |
| 67 gsm | 45 lb. text |
| 89 gsm | 24 lb. bond, 60 lb. text |
| 104 gsm | 70 lb. text |
| 118 gsm | 80 lb. text |
| 148 gsm | 67 lb. bristol, 100 lb. text |
| 162 gsm | 60 lb. cover |
| 163 gsm | 90 lb. index |
| 176 gsm | 65 lb. cover |
| 178 gsm | 80 lb. bristol |
| 199 gsm | 110 lb. index |
| 216 gsm | 80 lb. cover |
| 219 gsm | 100 lb. bristol |
| 253 gsm | 140 lb. index |
| 263 gsm | 120 lb. bristol |
| 270 gsm | 100 lb. cover |
| 307 gsm | 140 lb. bristol |
| 308 gsm | 170 lb. index |
| 325 gsm | 120 lb. cover |
ไม่มีความคิดเห็น:
แสดงความคิดเห็น