For me, about a week, but I have a nose like a vacuum.
Just wondered, is it better to use blocks of chalk or bags of powdered chalk?
I know i can get a block of 8 (400g) for £13.00, whereas a 250g bag is £3.99
I use powdered because it was available at the store. I’d prefer solid because it’s less messy, but theres no huge difference either way. When I eventually run out I’ll try liquid chalk