✔ 最佳答案
二層的英文是 split leather
I've found one of the article and now post it to you for reference :)
English
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Main Business: ..... We select best grain and split leather to produce leather work glove with best quality.
Chinese
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主要業務: .....我們選用上等的頭層皮和二層皮來生產出高質量的勞保手套。