Vridar

Clifford L. Blodget's The Sewing Machine Master Guide states the upper tension should be lowered in comparison to a SS when ZZ stitching. SS the thread stitch lock is to be in the material. He indicates it's not important on the ZZ and a better stitch results. He writes that the wrong side is not important. I have always tried to match the ZZ stitch tensions resulting with thread lock in the material. Often this is difficult.

What is the consensus of QB members?

Edit: to make this Vintage Machine topic appropriate, I should state I'm working with my 206 and 306 ZZs.

NapaJohn

I've always tried to balance them. It looks better. However, I don't sweat it if it pulls to the back somewhat. It's more important not to make it so tight that it causes the fabric to pull/bunch together. For something like machine applique, that would make the background fabric not lay flat.

Cari-in-Oly

Some say the stitch should be balanced, some say the top thread should show a little on the back. I do whatever it takes so the fabric doesn't tunnel. Using a stabilizer with thin fabric helps, even if it's just a piece of paper. I'm inclined to believe that the top thread is supposed to show a bit on the back because with embroidery machines where you have a lot of satin stitches and just dense stitching, you're supposed to have the top thread show 1/3 to 1/2 of the stitch on the back.

Cari

miriam

I struggle with this on some machines more than others. It is hard to get the tensions balanced. I think it is better to go for a stitch that is pleasing.

Candace

The top thread should pull more to the back for zz and decorative stitching. It does mean lowering the top tension from a regular straight stitch.

quiltedsunshine

At the shop, we balance tensions with the zig-zag stitch. If we balance so the top thread is just a "tick" on the back, the straight stitch should also be balanced. That's where stitch quality shows up -- in being able to balance the zig-zag stitch. Those cheap, plastic bobbin case machines are a lot harder to balance the zig-zag. The "tick" on the back can be so uneven. But I'm learning that people would rather have a cheap machine with bells and whistles than good stitch quality. There's nothing like an oscillating hook for great stitch quality!

Vridar

Thanks. Balancing this way seems to work.