Any ideas?

Spray cleaner doesn’t work.

Not tried WD40 yet!

Repaint the wall & keep the tub for when it happens again!

bleach spray?

try some other solvents
acetone/nail polish remover
paraffin

hit fairly firmly with a stick or belt

– won’t clean the wall but might prevent a repeat 😉

Washable pens FTW

White spirit usually works, but you will take some of the paint off with it.

You could try IPA, but it will probably take most of it off, but leave a faint smear.

Although, emulsion or gloss?? Emulsion will probably end up in a smeary mess.

Baby wipes, worked for us. Probably depends on paint & ink.
Good luck!

Give them more pens, let them have more fun, then repaint

take the opportunity 🙂

^ good point, baby wipes are amazing. Lord knows what’s in them, but they seem like a universal solvent 🙂

lightly sand the wall 😉

worked for me on ANY dirty mark in rentals.

baby wipes are ace for cleaning chains 😉

dampened felt cap on childs head

Washable pens FTW

I read that with an ‘i’ in it and wondered how that might help the OP……

If all the above fail, try nail varnish remover, lost count the number of bits now I have cleared up with it.

weird, I was just watching this before checking STW

video here:

http://www.debutart.com/motion/jon-burgerman/aol-nyc-mural#/motion-portfolio

hit fairly firmly with a stick or belt

– won’t clean the wall but might prevent a repeat

I like that.

Buckle end?

Go over it with a whiteboard marker. The solvent that makes it non-permanent should lift it.

‘s what you do when people use permanent markers on whiteboards anyway. With kids’ pens and a porous surface it might not be as effective. I’d probably have a punt though.

try using a spray deodorant something like lynx works great with permanent marker so should work

Try an eraser. It is a bit like sanding but less aggressive. Worked from me in rentals when there were tyre marks hall wall.

Use some of your handy 5L tin of paint thinners. Doesn’t everyone have one?
Either that or maybe brake/carb/glasses cleaner
It will however stink the house out and make everyone mildly high.