Do I really need to buy fabric pens, or will felt tips do to decorate teddies T shirts?

[jollyholly]

DD1 is having a build a bear birthday party and decorating the t shirts.

Do I really need to fork out on fabric pens for 10 kids, or can I use felts? I know they won't wash, but is there another problem?

Thanks

Just the washing, I think.

Ok, thank you