It’s possible to sew a doll body flawlessly, then have it lose all shape after you start to stuff it. Stuffing can be inserted too fast and become clumped in tight masses. And sometimes certain parts will be strangely hollow, like just inside the seams, or near the shoulders, or around the hands or feet. It doesn’t matter if the shape you sewed was perfect; the finished doll will look lopsided. Think of stuffing not as an afterthought, something you do after the doll body has been completed, but as an integral part of forming the doll itself.
Stuff the doll using small amounts of stuffing. You can pull the stuffing apart slightly to keep it fluffy and light. Then insert it little by little through the turning hole. Use a blunt turning tool to get the stuffing into the narrower parts. Don’t force it too hard, just push gently. When filling an arm or leg, start by working toward the far end and build the shape back toward the opening.
Often a hard lump will occur when new stuffing is added right on top of old, compacted stuffing. If there is a hard lump, stop adding stuffing. Use your fingers to rub the area and distribute the stuffing outwards into adjacent hollow areas. Sometimes it is easier to remove a bit of stuffing, and restuff the area slowly. Often adding more stuffing on top of a hard lump will make it even harder!
Take two scrap-fabric “tubes” or dolls to practice with. Quickly fill one with several big handfuls of stuffing. Then take a few minutes to carefully fill the second doll. After each small amount of stuffing, turn it over in your hands. Now press the front, back and sides of each. It should be easy to tell the difference in how well-stuffed each tube is.
If a hollow area remains, you’ll have to address it differently. Check along seams and near transitions of shape, like where the doll’s belly curves into her neck, or the thigh bends into the lower leg. The stuffing might not have reached those hollow places because the opening was too small. Put some stuffing in there and check the result. If you are making a pair of arms or legs, stuff them simultaneously so you can compare the thickness and density as you go. Otherwise you will have to try to match the fully stuffed limb.
Before you close up the turning hole, hold the part up to the light, slowly turning it. Feel the surface carefully with your fingertips, and don’t judge it purely by sight. Don’t try to make the doll body firm, try to make it uniformly shaped and proportionate. There shouldn’t be any hard bumps, or holes that collapse easily. When your fingers move across the doll smoothly, and don’t suddenly feel a hard lump, or an empty spot, then you can close the turning hole.