Dab tsi yog Mark Pen

Tus cwj mem kos yog ib tus cwj mem uas tuaj yeem sau lossis cim rau ntawm daim ntawv, ntoo, hlau, yas, thiab enamel ceramics. Cov cwj mem muab faib ua cov cim oily thiab cov cim dej-raws li. Tus cwj mem dej-raws li cim tuaj yeem sau rau ntawm qhov chaw ntawm cov khoom du lossis ntawm daim ntawv dawb. Nws tuaj yeem muab tshem tawm nrog ib daim ntaub (whiteboard cwj mem). Lub cim oily tsis yooj yim rau lwv.