I've got an ornament about 30" high that I'd like to make a plaster cast of. What's the best way of going about this - I've read about painting on layers of latex... or should I look to using alginate? I'm totally new to all this, so advice would be very welcome!
Also depends on the complexity of the shape. If there are lots of twiddly bits it may not cast very well, or leave air pockets etc. You may have to make a multi-part mould. Try your local library under the Art & Crafts or hobbies section.