On any and all incisions - most especially the main incisions ... dorsal or ventral (belly) - I use an "Upholsterers" Stitch
- the "Invisible" Stitch
- to close the skin. It draws the skin down and in on itself, literally making it "invisible."
Start by knotting off the thread, go up on one side. Come back over the top, and go down through the opposite side ...
Go up through the same side the needle just passed through!
Cross over to the opposite side, and pass the needle down through the skin from the hair side ...
Keep the thread from catching the hair or fur, and pull the thread down ...
... then again up through the flesh side of the skin on the same side the needle just passed down through.
Pull together the two or three stitches just made. You can continue, or - my recommendation - knot off the thread, and then continue. Basically it's like 'rinse and repeat', but in this case it's 'stitch and repeat'.
If you grind a shallow groove in the top of the mannikin's back, the length of the incision, fill it with clay, the sewn incision can be pressed into the clay further hiding it. You can use a rubber mallet and gently
tap the seam flat into the clay. Insect pins can further hold the skin until the mount is dry.
On some mounts I will even use this stitch to close the legs! On very thin tanned skins I use either 3-0 or 4-0 Silk Suture and this particular stitch to close these incisions. Keeping the hair or fur out of the stitch is the key, and is much easier than you might first think!
It's more work than just carefully sewing an incision together, but then again, you have a damn near flawlessly sewn mount.
There you go!