The proverb you can’t make a silk purse out of a sow’s ear means you can’t create a fine product from inferior materials.

I'd argue it's closer to 朽木不可雕^. 巧婦難為無米之炊 (巧妇难为无米之炊) is more like you can't make stuff without the necessary requirements.

^朽木不可雕: Lit. Rotten wood can't be carved, metaphorically You can’t teach a student that is too dumb.

... Well actually no. Upon looking into these 3 idioms further while composing this comment, I leaned more and more towards that 巧婦難為無米之炊 is actually closer. Why? Because 朽木不可雕 applies only to humans and it puts more of a focus on the rotten wood (aka the dumb student).

I guess this comment was kind of useless lol but I decided to post it anyway because I put in way too much effort