Bohin Twin Eye Chenille Needles - Sizes 18/22
The double eyes are meant to carry two different threads, allowing you to either blend threads, or add in metallics without putting friction on the fabric. This should result in a neat almost railroaded blended thread look.
The double eye makes blending a metallic with floss much more pleasant - definitely worth a try!
Package of 6 needles - two each of sizes 18, 20, and 22.