Interfacing is another piece of fabric (woven, non-woven or knit) that is used to stabilize a fabric and/or give it more body.  It is commonly used in collars, cuffs, lapels, waistbands, under buttons and under zippers as well as in many craft and accessory projects.  Interfacings can be attached through fusing or sewing.  When you buy an interfacing, always check to see if it is fusible or sew-in.  Fusible interfacing will have small dots of glue on the wrong side.  Be careful not to iron on the wrong side as it will stick to your iron.  Sew-in interfacing must be basted to the project fabric to stay in place while sewing.

We will be using a fusible knit interfacing to stabilize the center front seam allowance where we will be applying the zipper.  This will prevent your fabric from stretching while you apply your zipper, creating a wavy zipper down the front of your hoodie.  The knit interfacing we will use, Pellon Sheer Knit SK135, is stretchy going crosswise and stable going lengthwise.  Knit interfacing is applied in a very similar manner as woven interfacing.  When you stabilize your seam allowance correctly, the knit fabric will behave more like a woven one. 

When applying interfacing, Follow these steps:

Heat, Steam, Pressure, Time

  1. Set iron to wool setting.  You may need it a little warmer to have the glue beads melt.  Always test it out.
  2. Press fabric
  3. Lay press cloth on ironing board
  4. Lay fabric face down on press cloth
  5. Lay interfacing, bumpy/glue side down
  6. Cover interfacing with press cloth
  7. Use steam (spray bottle, damp press cloth, iron steam)
  8. Steam baste interfacing on fabric (press down on edges)
  9. Press iron on press cloth 10 seconds
  10. Move to new area and press, don’t slide iron
  11. Steam press on right side
  12. Let cool

It is always best practice to make a sample to test your interfacing.  To make a sample, follow the steps below.

Supplies needed:

1 – 6”X5” piece of knit fabric

1 – 6”X5” piece of fusible knit interfacing, trim off ¼” of seam allowance

Steps to complete:

Using the proper techniques listed above, fuse the interfacing to wrong side of fabric.


Would you like to learn more?  Check out the resource library.

 Once you have tested your interfacing, you are ready to apply it to your hoodie. You will apply your interfacing to the wrong side of your Front pieces along the center seam.  You will see in the video that I have my pockets sewn on.  You will not have sewn your pockets.  So apply the interfacing at this step in the same manner as the video.