Stabilizing Primaloft 1.8 in quilt, could use some advice

I asked Primaloft

They said – Primaloft One requires 3 inch quilting in each direction for weights less than 100g/m2 (4.25 oz/yd2), and 6 inch quilting in each direction for weights more than 100 g/m2

So, you have to make a row of stiches every 3 inches in both directions

Personally, I think this is overly conservative. You mostly just need to quilt across the fibers in the insulation. If you quilt every 6 inches it would probably be fine. But that's based on very little experience with a piece 14 inch square I was testing.

Or, if you made a loop on 6 inch grid like you said, that would probably work. The insulation might shift over time.

I have not made a quilt, but I have made pants. The 1.8oz stuff is very very light. Its the same stuff that is in the nano puff. You may want to size up unless it is a specialty quilt.

My understanding is that 1.8 oz needs to be sewn in 3 in^2 squares. 3.0oz and above is 6 in. No quilting loops needed to stabilize.

Thanks for the quick answers. it is actually the 3 oz/sqyd, i miswrote that in the title and upon editing it looks like it didn't change on the main forum page.

I think I might go to 5 inch squares and see how that holds up.

Surely if you simply sew a set of stabilising lines in one direction, that will be fine?

Aren't we simply trying to stop the wadding moving about, and sewing in one direction only should do that adequately?

I made a pair of Thinsulate salopette liners in 1997, and didn't use any quilting at all, and the wadding seems to have held up okay. It's a lot thinner than it used to be, mind, but I suspect that's a different issue.

Primaloft told me to sew 3 inch squares – rows of stitches in both directions

To me, the rows of stitches that parallel the fibers of the insulation won't do much, because you can easily pull apart the insulation in that direction so it won't do much

Maybe they're just being conservative. If they said to sew across the fibers of the insulation, some people would mis-interpret and sew parallel and it wouldn't do what it's supposed to and people would complain

Maybe they say 3 inch spacing because some people really abuse their garment, and if you're more careful you can get away with wider spacing.

Maybe with narrower spacing, after a few years, the insulation would be a little more uniform, but not a big deal for normal use

> To me, the rows of stitches that parallel the fibers of the insulation won't do much, because you can easily pull apart the insulation in that direction so it won't do much

But once you've sewn the wadding to the shell fabric, it's the (inelastic) shell fabric that will stop the wadding being pulled apart. Wadding fibres aren't generally linearly aligned; they're usually randomly oriented.

For garments, I'd be tempted to quilt to just one shell face, on the grounds that quilting loosely to both might 'saw through' the wadding when the inner and outer shell fabrics move relative to each other.

Maybe I don't understand what action you're trying to protect against. And then there's Primaloft and there's Primaloft; some variants have a scrim that I thought was supposed to eliminate the need for quilting…

"Wadding fibres aren't generally linearly aligned; they're usually randomly oriented."

One, Apex, and Primaloft Sport, all have fibers going primarily in one direction

Take a piece, try to pull it in one direction and it doesn't stretch much, pull it in the other direction and it pulls apart

> One, Apex, and Primaloft Sport, all have fibers going primarily in one direction

Aha. I've only ever used Thinsulate, which is pretty random.

So, single axis quilting perpendicular to the fibre alignment, then?

The Primaloft people say same quilting in both directions – a square grid.

But, it seems to me like only the rows of stitches that go across the fibers make much difference, so that's all that's needed, but that's just the opinion of a non-expert : )