Typically women wait until they are in the last few weeks of their pregnancy to make a
belly cast.
Women usually want to remember their largest, roundest belly, not their cute little one at 5 months. The belly cast you are going to make will be a mold of the front of your body. Some women choose to do their breasts/chests and stomach, while others stick with just the tummy. If you are really motivated, you can even do your arms! But that is up to you. Typically women stick with just the tummy.
To make your belly cast you will need to have your helper with you. This can be a fun, intimate way of sharing your growing belly, and baby with your husband as you await your bundle of joy's arrival. Before you begin, make sure the momma is comfortable. This takes a little bit of time, so go to the
bathroom, eat something and get a drink.
Start by placing newspapers on the floor around you and protect the chair with the drop cloth. You will use a shallow basin of the room temperature water, and a sturdy pot. Place these near the pregnant mamma. Open 2 rolls of plaster, and cut into strips 12-18" in length. Set the strips aside and cut out at least one square (2-3"). If you are doing your chest as well, cut an additional 2 squares. The squares accentuate the belly button and nipples, if you are doing them.

Now you are going to spread the vasoline over the parts of your body you are going to cast. This ensures that the little hairs covering your body do not get stuck to the plaster (this would make for a very unpleasant experience). Use a piece of plastic wrap to protect underwear or pubic hair. Mom should be sitting straight up and away from the chair, so the belly cast won't touch. The helper (your husband) should put on the gloves now.
Next, he will want to wet the plaster strips one at a time by placing them in the water basin and then place them across the area to be molded. When doing the nipples or belly button, use the square pieces and mold them over top to show detail and emphasis. You will put several layers of plaster strips over
the entire belly, but will not put additional layers on the nipples or belly button. Smooth the strips and remember more strips means a stronger cast.
It takes close to 10 minutes for the belly cast materials to begin to dry on the pregnant woman's belly. The mamma will have to stay in one place until the cast is set. You will know when the cast is done when it gets warm, heavy, hard, and begins to pull away from your body. This takes about 30 minutes. Remove carefully and lay, belly up on a surface to dry thoroughly for about 2 days.

What You Need
WHAT YOU NEED:
1 plastic drop cloth
1 jar vasoline
1 pair gloves
3-4 rolls of plaster material (ea. 4" x 5 yards)
Basin of water (room temperature)
Chair
Someone to help you
ADDITIONALLY YOU MAY WANT:
1-2 paintbrushes
Paint
Glitter
Anyother item you want to decorate with