Just bought these chalk pens because I bought the Flower chalkboard for my fridge and thought I would need spares. Assumed that the pens were going to write properly when held vertically. But I can only get them to write very short words or part of a longer word before the writing starts to fade. For example I just tried to add ‘washing up liquid’ to my flower board shopping list and got ‘washing-u’ before the white ink almost disappeared. The only way to write more than this is to stop, hold the pen downwards, wait, and then start again. Absolutely love the board, disappointed with the pens.