There is a BIG difference from pin to pin. If your pins are too big, too thick or not sharp, you will distort your patchwork before you even begin to stitch.
If your pins are too short or too fine, they are difficult to use.
I love these glass head pins for the vast majority of patchwork sewing that I do. The heads don’t melt when you iron them by mistake. They are just fine enough, they are long enough and they are sharp. The stats: 1-1/2″ long with a .50 mm shaft. The perfect pin storm. These are by Collins. Ask for them at your local quilt shop!