After reading Mabelle's blog ,Whimsy And Stars Studio, it reminded me of how much I loved creating rubber stamp designs. When I first started illustrating professionally , I found designing rubberstamps to be a fun way to be paid for creating artwork.
Here are some I did primarily for a company called , "The Merry Stamper", a line called , "bearz by roz". 
I don't know how it is done now, but when I was designing images , I would query (by email) rubberstamp companies and see if they worked with freelance illustrators. If they said yes, I would send them a link to a page of artwork with prices.
This is a great way of recycling line art that you may have tucked away in your files.
If you decide to give this a try , be sure and only sell them "rubber stamp rights" and retain the copyright. There are a couple of routes you can take as far as payment. flat fee, royalties only or the ideal situation, pay and royalties. It all depends on the company and they will provide that information for you.
KERCHUNK - A list of rubberstamp companies.
It was fun looking at these stamps. Makes me want to make some more. Here's my favorite: 
How cool! I wanna do it! What made you stop?
Posted by: Snowbear | March 21, 2005 at 07:33 AM
Oh WOW, Roz :-)
They are soo wonderful. You have such talent! :-D
They look like soo much fun!
Posted by: Tine | March 21, 2005 at 07:35 AM
Just time constraints. I was spending more time on creating stamp designs than working on my children's illustration portfolio. I still keep meaning to gather my little spot art sketches laying around here and ink them in. It's on the "to do" list. THE NEVER ENDING "TO DO" LIST! hahahaha
Posted by: roz | March 21, 2005 at 10:27 AM
Oh your rubberstamps are just gorgeous!! I too designed some for the Angel Company and had a blast doing it too! Mine are up on their site now. Like you i can't wait to have samples sent to me so i can play with them!
Your bears are so adorable!!
Love, Violette
Posted by: violette | March 23, 2005 at 09:16 AM
Those are so sweet, Roz!!
Posted by: janee | March 23, 2005 at 01:16 PM
Oh, they look wonderful! Thanks so much for sharing your resources with us! I've been researching for months on doing rubber stamps and decided last month I'd just come up with my own line, but this is an open window I'm going to pop my feet through soon! Thanks!!
Posted by: Giao | March 24, 2005 at 03:04 PM