Hi Charmaye, yep you’re right, with oil based (non drying) clays you can re-use the clay. -Just pick the clay off the armature and start again or continue working on the piece and transform it into something different :) (May need to warm the clay with something like a hairdryer if it’s particularly thick and hard to remove) With a clay like Chavant nsp/Monster clay…you can in theory have a piece on the shelf and come back to it a year later and keep working on it….(cover from dust though). Polymer clays like Sculpey/Fimo are workable till they are oven baked to ‘set’, so are reusable, but unbaked they will dry out over long periods and start to crack ( like months not weeks). Dry and crumbly clay can be nursed back to health with some conditioning. Sculpey has a product for this ‘clay softener’, in a pinch I’ve had success with baby oil and lots of kneading. Air dry ‘pottery style’ clays (water based) can be reworkable if kept moist, wrapped in plastic between work sessions, however I reckon feels best fresh out the packet. Hope that helps, have fun sculpting!