We often receive questions about which needles we like to use for applique. The answer is that both Nancy, Janice and Connie use John James Milliner (aka Straw) needles in either size 10 or 11. A size 11 needle is slightly thinner than a size 10, and works very well with tightly woven fabrics, and with batiks. Because a size 10 is not quite as thin, it does not bend quite as easily, and is often preferred by beginners. (Speaking of bent needles, we do not fret over bent needles anyway. We think a needle with a slight bend helps to keep the thread from twisting.)
The length of the Milliner/Straw needles aids in turning under the 3/16" edge of fabric when doing needle-turn applique. With a shorter needle there is not enough length to hold the needle and have sufficient needle to sweep the fabric edge under.
Needles are often labeled according to their assumed intended use. Thus, Milliner/Straw needles were originally used by hat makers (milliners), presumably for making straw hats. More recently we see needles labeled as 'applique' needles.