Sunday, June 23, 2013

How To Use a Seam Jack

If you're sewing over bulky seams, a "seam jack" can be your best friend.

A "seam jack" or "jeans jack," can be purchased where sewing machine accessories are sold.  The middle one is Bernina's “height compensation tool,” which you can buy at your local Bernina dealer for about $1.00.  Or you can fold some light-weight cardboard or plastic to a thickness of 1/16” to 3/16.”  

The reason we have a hard time getting a good stitch, or with breaking needles on thicker fabrics, is because the presser foot tilts as you go over a thick seam.  A seam jack helps keep the presser foot even, so that the connection to the feed dogs  underneath is even. 

#1.  As the presser foot tilts, it loses its grip on the feed dogs, and the needle gets pulled into the presser foot or needle plate.


#2.  As you approach a thick seam, put the needle in the down position and lift the presser foot.  Insert the seam jack right behind the needle, and let the presser foot back down.  Sew across the seam, and stop with the needle in the down position. 

#3.  When the presser foot is sitting evenly, on top of the seam, and about to start tilting forward, as it goes down the other side of the seam, put the needle in the down position, lift the presser foot and remove the seam jack.  

#4.  Place the seam jack under the front of the presser foot, but only under one side. 

#5.  Let the presser foot down, and continue sewing until the back of your presser foot is ready to sew off of the seam. 


  1. Thanks! I was never really sure how to use those items and didn't know why they worked. This will certainly make my sewing life easier!

  2. Could I just use a walking foot? They sew over bulk pretty well.

  3. thank you… great explanation

  4. Really the blog is so informative about the sewing machine keep on posting new blogs I am looking towards the new blogs.

  5. So I just tried to post a comment here but I don't see it so I am going to try again. If it doubles up sorry.

    I've been looking for one of these tools everywhere. The only places I can find them are in photos and videos showing how to use them. I've searched the following- pressure foot spacer, jeans jack, seam jack, height compensation tool. The best one I could find are shaped like a U. I will be ordering one of those. What I really want are the kind that have the metal holder that has 3 pieces of plastic(the middle one in the photo you have here). I know there is also a jean amajig and hump jumper but these are huge and not what I would prefer. I am working small. Any help? I've tried Ebay, Etsy, Amazon and google searches. Nothing.

  6. The middle seam jack is a Bernina "height compensation tool," and can be purchased at your local Bernina dealer for about $1.

  7. Hi!
    I found a link to your Post on Pinterest & Grateful for it! I very much could use something like this for my Brother (lower-end, CS600i). I have a walking foot (which I'm horrible about using!) but, I'd prefer to use my open toe whenever possible using something like this!!
    Going to start searching and hopeful to find one that works/fits!!

    ** QUESTION ** - Once I've made it over the "bulky part" using the Seam-Jack, Why must I then, "...Place the seam jack under the front of the presser foot (but only under one side) until foot is ready to sew off of the seam...." ?

    Thank you so much for your time and for the Info,

    1. Hi Sharon,

      If you don’t put the seam jack under the front, the foot will tip forward, and you’ll break needles and skip stitches. If you put the seam jack fully under the foot, in front of the needle, you’re likely to sew onto the seam jack, and break a needle. So, you want to stabilize the foot as it sews OFF of the bulky seam, in the same way you stabilize it when you sew ONTO the bulky seam. And put the seam jack just under one side, so you don’t sew onto it. I hope that makes things a little more clear.

      Thanks for asking!

    2. Hi, my machine is recently sewing backwards and very slow, what might be the problem..

  8. Foarte bune indicațiile. Mulțumesc frumos!

  9. Excellent tips, thank you!!! Now I know what that plastic thing is that came with my bernina machine.. 😃 Leila

  10. I use an emery board that has a plastic covering and it works great!

  11. Thanks for all the information you have provided with this blog.It is really helpful!