The decorator ordered inserts that were 16" diameter, and guess what, there is no pattern available for a ball pillow that size- so I had to draft one.
If you look at math websites, or, alternatively, globe websites, you can find how to draw the pattern, but unfortunately they don't give precise proportions for the curves.
I figured I could use the insert for a rudimentary pattern, and refine it from there.
The softest, most flexible material I had readily available was- Kleenex tissues!
Pinned to the pillow, they draped around the sphere, and were easy enough to see through to mark the seamlines.
Then I transferred the shape to pattern paper and evened it out- you can see how lopsided it was at first- this took several tries; then added a 1/2" seam allowance.
Making a mockup out of lining was essential. It's nice to have a gridded tabletop, and lining you can see through so it was easy to cut on the grain.
The mockup needed refining. I thought it was a tad too big, and about halfway up the curve needed to be trimmed down a little to improve the curve.
Before cutting the silk velvet, I used Rowley's fusible fabric stabilizer on the back. Then marked and cut 16 sections, cutting as carefully as I could, and notching VERY carefully. The notches were critical to a good outcome.
Sewing the pieces together is simple enough, using the notches as a guide. It is extremely important to keep the dots at the very tips precisely aligned, so you have a beautiful apex.
All 8 sections sewn together, one side is left unsewn so the insert can be stuffed in.
It would've been fun to have a video of me stuffing that insert into the cover, but I would've been extremely embarassed. You really have to wrestle with it. But it did happen, against my initial misgivings. I sort of rolled it into the cover. I pinned the open edge, using the staystitching and notches to keep things where they belonged.
Hand-sewing pillows closed is NOT my forte. The curve required the teeniest stitches- like, 1/8". I sat and watched the Yankees (yes, there's Joe Girardi on the screen in the background.)
I have a new favorite thread: Coats' Outdoor- and it was available in brilliant orange! It doesn't tangle, doesn't shred, knots securely, and comes in a lot of cool colors. I'm going to stock up on every color.
If the tips are all aligned precisely, the pillow ends will look like this: