Stop Color Transfer: How Laundry Sheets Work

[wolram]

According to the adverts one puts this sheet of whatever it is in the washing machine and it stops color transferring to other clothes in the machine, so how do they work?

 

[Bystander]

Charcoal, activated carbon, or some other adsorbent?

 

[dlgoff]

Maybe it works similar to a photographic film fixer.