I personally have never tried clay from the arts stores. I have only used it for making arts and crafts when I was little.
Just keep in mind that the clay you are using may leave significant marring from claying. They do not have the same regulations as vehicle clay. Particulates that may not be off concern for art usage is a huge concern in vehicle usage. Would I use it on clients vehicles or recommend it? No there are not enough regulations in place to make sure that clay for art usage meets the standards for vehicle usage.
The Riccardo Yellow and Blue clay bars that I sell contains three bars. For a vehicle that is clayed at least twice a year you will only need half a bar for each application. That being said you would only need a package for 6 applications. If the vehicle is extremely contaminated due to the area the vehicle is in ie. train tracks or industrial areas you may need to use a full bar instead of just half. The Riccardo Yellow Clay is $22.99 for 8oz.
I find the meguiars clay products from Canadian Tire are overpriced. You get one bar and some clay lubricant. From a value stand point you are better off buying the clay and clay lubricant separately. Riccardo and Optimum No Rinse or Chemical Guys Quick Detailer make great clay lubricants.
However all of this being said. I'll pick up a few bars from varying stores and do a test on spare vehicle panels about marring and consistently.
Last edited by Nikku; 01-28-2010 at 11:07 AM.