If you're old to enough to remember blackboards - or chalkboards if you prefer - were the stalwart of the classroom, allowing the teacher to write with chalk onto a black (or sometimes green or blue) matt surface. The teacher would just wipe off the chalk with a brush or damp cloth and start again.
In crafts it's great for re-customising projects easily and is also great for using around a busy home or office - a bit of retro for old style reminders. Choose from tape, stickers, pegs and even paper if it's just the blackboard effect you're after.
