I have a collection of watercolor eggs that has slowly grown over the years. This year I painted a fern egg to add to the lot. These are blown eggs--the whites and yolks have been removed.
Although they are quite fragile, blown eggs will last for years if treated gently.
If you've never blown an egg before, it's easy to learn!
Use a needle or safety pin to poke a hole in the top and bottom of the egg.
Make sure the hole is 1/8 inch or so in diameter.
If you are having trouble getting the whites and yolk out, make the bottom hole a little bigger.
(No, I'm not losing my dinner.)
Then gently (but with quite a bit of force) blow through the top hole.
The contents of the egg will pour out the bottom. Now you can make scrambled eggs!
Rinse the egg shell and let it dry thoroughly. Then paint, sketch, dye, create!