| 摘要 |
A process is provided for creating a watermark on a polymeric sheet. The sheet is passed between abutting rollers, at least one of said rollers having a recessed and/or raised motif, to form an impression on the sheet corresponding to the motif, and then orienting by stretching the sheet. The impressed and oriented sheet has dark areas corresponding to the raised portions and light areas corresponding to recessed portion of the motif.
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