I use this stuff to sculpt onto pretty much everything for my small business: clay pots, canvases, recycled glass bottles, and more!Tips:1. Cracking...so you can't really prevent it. But there are east ways to fix it. For example, My process for sculpting faces is simple. I work in sections. First the nose. Then the eyebrows, cheeks, lips ect...make sure to smooth your seams with A WET PAINTBRUSH... I like to dip my brushed in water then wipe them off on a sponge.Now, let your project dry for at least two days in a low humidy area. In that time, Your project will most likely crack or separate at the seams. At this point, you should make a very thick paste with your clay and use a paintbrush to fill in the cracks and smooth it out as if you were using caulking.Let your project dehydrate completely before sanding, priming, painting and sealing.2. It's important to work in sections and smooth out any imperfections while the clay is still wet with a paint brush or sponge to prevent cracking or crumbling anywhere other than the seams around the sections.Working in sections also prevents other parts of your project becoming dry and clumpy before you can add any further details. You'll understand what I mean once you work with it more.3. To make your clay easier to work with...remove the block from the original package and place it in a zipper top bag. Now, and about a tablespoon of water. No more, and possibly less depending on how moist your clay arrives. Let the block sit with the bag sealed for at least an hour, drain any excess water then begin your project by taking pieces from the bag and reasaling it each time you go for a new piece. You will eventually find your preferred texture the more you get to know how to clay behaves.4. Painting and sealing....I can't stress enough how dry your clay needs to be to successfully create a project that will last. Don't rush it! No matter how dry the clay seems, I can assure you that there is still moisture in there! While your Paint might go on really nicely at first, it will most likely peel off a week later or even sooner if you place it outside because the moisture in the clay began to wick it's way to the surface.I recommend that you follow the steps above for fixing any cracks and then after two days of room temperature drying, place in your oven at 200°-250° for at least 2hours. More or less depending on how thick your project is. The point in this is to dehydrate the clay completely. Then, let cool in the oven. DO NOT TAKE IT OUT RIGHT AWAY! Wait until it's warm enough to take out then WHILE ITS STILL WARM/HOT...I REPEAT...WHILE ITS STILL WARM/HOT... spray/brush on a good sealing primer. Making sure to get in all the crevices! This will prevent the clay from absorbing any moisture out of the air. Trust me. Any bit of moisture will ruin your paint job in the long run. Add two to three coats of primer before painting.5. Sealing...seal small projects with deco art glaze and bigger outdoor project such as pots with Rust-Oleum crystal clear enamel.Hope this helps!