I just had a stroke of brilliance!
I change my curtain every
other month anyway (I like dollar store white curtains so I can keep
them clean) so why not write on it?
I am in the process of writing our spelling words, some vocab, etc
etc. on the shower curtain.
We'll use that one for a month or two while I have my kids write
on the new one that will be used later.
That way we'll have recurring notes that we see every day. I'm not
sure yet if we'll be able to write on both sides. Probably not.
I used permanant marker and it hasn't come off.