4.0mm size 75 stretch on grey knit velvet – skips lots of left stitches and tangles. On quilting cotton – works fine (despite being stretch needle on non-stretch woven)
2.0mm mystery needle (came with machine) – fine on quilting cotton. On grey knit velvet – both needles skip stitches, especially left one, and threads tangle.
4.00mm size 80 ballpoint on grey knit velvet – left needle managed to make only one single stitch. Quilting cotton still fine.
At this point I got fed up with the grey velvet and hunted out a different knit velvet scrap to try – a crushed velvet dark petrol/teal that is much poorer quality than the grey. But the size 80 ballpoint worked fine in it. Tunneled up a bunch, but made every stitch.
(turned the top tension up to 3.5 while trying to fix the tunneling and instead it started to skip the occasional left stitch. So keep the top tension low? 2.5)
Additionally the tunneling is only really noticeable on grain, whereas running on the cross-grain it barely happens at all. Either way the twin stitching still builds in enough stretch to keep up with the fabric.
In conclusion I’m none the wiser as to why the grey knit velvet hates all the twin needles. But I have managed to test and find a needle and stitch that works for my next project (joggers muslin with the petrol-dark-green crushed velvet), so that’s a win. Good enough is good enough.
to the touch 