Cultured and natural pearls will feel slightly rough , like fine sandpaper , because of the texture of natural nacre.

天然珍珠和人工养殖珍珠会有些许粗躁的感觉，如同细砂纸般，那是真珠质的天然触感。

youdao

We have a fun way of looking at it: Let's say you have a piece of very fine sandpaper, and you rub it with your fingers.

我们有一个有趣的方法看这件：让我们说，你有一块非常细的砂纸了，你擦它与你的手指。

youdao

First of all, to deal with some spraying petrol, acetone for degreasing treatment with a file, fine sandpaper, oilstone will fatigue layer and oxide layer removed to expose the metal color.

首先应对喷涂部分用汽油、丙酮进行除油处理，用锉刀、细砂纸、油石将疲劳层和氧化层除掉，使其露出金属本色。

youdao

They had to be planed, rubbed with fine sandpaper, polished with paste wax, to a soft and glowing evenness.

ECONOMIST: Alan Peters

The blocks themselves, made from the fine-grained wood of pear or jujube trees, are cut to a thickness of two centimetres and polished with sandpaper to prepare them for engraving.

UNESCO: Culture