Thanks Alex for asking for a tutorial on this technique. Again, my demonstrator friend Cheryl showed this the other night and I thought it was a very fun way to use the chalks. So, here goes:

Step #1. Gather your supplies. You will need white craft ink, chalks, a wheel or stamps and dark coloured cardstock. I am using Elegant Eggplant for this little demo.
Step #2. Ink up your stamps or wheel using the white craft ink and then stamp on the dark cardstock. It is important to work with the ink while it is still 'wet' so the chalks will adhere better.
Step #3. I really like using the SU sponge daubers when working with the chalks. You can also use cotton balls, the applicators that come with the chalks or sponges. I punch out squares from scrap paper and place them over the colours I'm using so I don't get my colours mixed up. Anyhow, back to the instructions. Load up the dauber with the chalk simply by rubbing it on the chalk.
Step #4. Apply the chalk to the wet white ink. I like to dab the dauber on the ink rather than rub it in circles or lines. I find you get a cleaner, crisper look simply by dabbing.
Step #5. Use as many colours as you like for this technique. For my finished look I used Pale Plum and Old Olive on the Elegant Eggplant cardstock. Try different colour combinations.
Step #6. Create and assemble your card!
I'd love to see your creations with this technique. Feel free to email me a picture of your card! Thanks for looking!
Thought I'd answer a question that was posed on the comments today from Jean:
I am always looking for new ways to use chalks. Thanks. I just have one questions; When you use white ink, doesn't it blur as you chalk it?
I didn't find this happening, but when I applied the chalk I simply tapped it on top of the image and didn't rub or use a circuluar motion. I just tapped up and down. Hope this helps! Also, thanks Gerrie for suggesting using Versamark, I'll have to try that!