笔墨纸砚

筆墨紙硯
bǐmòzhǐyàn

brush, ink, paper and inkstone; Four Treasures of the Study

Wiktionary

Entry Composition

1 笔墨 bǐmò
  1. pen and ink
  2. words
  3. writing
=2 纸 zhǐ variant of 纸 zhǐ
=2 纸 zhǐ classifier for documents, letters etc

classifiers: 張, 沓
3 砚 yàn ink-stone