| 摘要 |
A process for modifying natural tracing paper to reduce its susceptibility to cracking on folding comprises the step of treating the paper with an aqueous urea solution of a concentration of at least 40% by weight, preferably about 50% by weight. The treatment is preferably carried out at the size press or bath of the paper machine on which the tracing paper is produced. The urea solution may also contain a surface sizing agent. The resulting treated tracing paper is particularly suitable for the production of envelopes, or packaging for luxury products. |
