As I mentioned last time, to make a do-it-yourself metallic thread, I intended to stitch the outline of the bat using two strands of stranded cotton and two lengths of a glittery 'holographic' machine embroidery thread.
And I'm pleased to say, it worked:
That's worked in chain stitch, and gives exactly the effect I was working for. On the downside, it's not much fun to stitch with! Even threading the needle is a pain, and the two different types of thread are determined to go their own way.
Still, it's looking like I want it to, and that's the main thing, so I'll persevere.