| 摘要 |
<p>The under sheet is partic. for meat products, being mainly of paper and cardboard. It has a layer of grease- and water-proof material on one side at least. This can be formed by metal foil, typically aluminium, or plastic such as polyethylene. The paper and cardboard can be corrugated, with a flat sheet on one or both sides coated with the material.</p> |
