I mentioned sharing some piecing tips from my Summer Medallion quilt (original pattern by Brigitte Giblin). The centre star and curved scallops were all English paper pieced. The star was a little tricky as it has a mix of slightly curved and straight edges. These were joined stitching from corner to corner following Brigitte's construction order diagrams.
I prepped my paper pieces using Sewline glue stick- see here. I needed to snip the bottom inner curve a little to give it room to stick down. I did the same on the inner curves on the clam shells.
There was a trio of 2 clam shells and one shield shape for each section. Here they are all pinned together in their groups of 3- paper clips are very useful for English paper piecing.
The outer scallops needed something extra than just hand sewing from point to point. I tried this and I couldn't get the inner and outer curves to fit, one was always ending way out of line with the other. I ended up stitching the top and bottom points of each curve I was piecing and then sewing the seam in between.
It sounds faffy but it saved a lot of time in the end as accuracy is really important in Engish Paper Piecing.
A whole area of clam shells could be sewn like this but an appliqué technique is often used. Mary at Molly Flanders has explored different techniques in depth- see here for more