Tips for sewing with foam (heavyweight interfacing)

The interfacing is something that “helps” you love or hate a project! It could be the best interfacing in the world, if you don’t use it correctly, it will give you only headaches!

The problem is that each project is unique, there are lots of types of interfacing so many problems may occur!

One problem that affects many projects is created by bulky seam allowances. For some projects it is not an inconvenience, while for others, it is a serious situation that you want to solve.
The solution? Keep the interfacing out of the seam allowances; it is easy to do this if you use fusible interfacing. But what to do if your interfacing is not fusible?

For a non-fusible foam (I used it for a pouch), follow the below steps:

• Cut the interfacing in the size needed.
• Cut the fabric 1” bigger on all the edges.
• Center the foam over the fabric; use an adhesive spray to keep the layers together.
• Sew from edge to edge of the fabric (do not start/stop the stitching at the edge of the foam).

When the sewing is done, trim the fabric at 3/8” (if that’s your seam allowance) away from the edge of the foam.

This technique works for simple projects (like pouches or simple bags), but if you have complex bags to sew, with lots of pieces to match, you have to use another technique. All that sewing/quilting shrinks the pieces, and if you need to match pieces for a bag, you have to ensure that the pieces shrink at the same rate (meaning, you have to do the same type of sewing on all the pieces).

Another technique that does not involve stitching is this: instead of keeping the fabric and interfacing together with stitching, use a layer of lightweight fusible interfacing (fusible side down)…

…and press.
Related tutorial: How to add interfacing to vinyl/ faux leather

Here is my boxy pouch stitched with the panel above. At my first try for this pattern I used the same foam, but without removing the seam allowances. There is a HUGE difference between the two techniques, when it comes to the easiness of the sewing.

I love, love, this quick and easy to sew pouch.
See below the difference the interfacing (and fabric) is making!

For the pouches below I used Decovil light interfacing and the same technique with no seam allowances.

…
but faux leather remains my favorite material for this pattern (it does not need any interfacing).

If you want to learn how to quickly and easily sew such pouches, click the link below.
Box Pouch Pattern

Happy sewing!