This guide to bag closures is written by Christine Down. Christine sells instantly downloadable bag making patterns at https://www.sewlush.org/
If you missed the previous parts of this series find them here:
Work out where you want your magnetic snap to be. Take the top of the magnetic snap, the bit with the oblong holes in it, and use this as a template to mark where the holes need to be cut. Carefully cut the holes in one piece with a seam ripper tool and push the front of the snap through from the right side of the fabric. Put the back over the prongs and push the prongs apart to keep the back on.
Cut a small piece of Thermolam sew-in interfacing and place over the snap back. Glue into place using fabric glue. Use the front of the snap to mark where the back needs to go. Attach the back of the snap in the same way. If you are closing the top of the bag by attaching the front to the back the snaps will be inside the bag attached to the lining.
In this case, cut out two ovals of firm iron on interfacing (or you can use other interfacing depending on what you have to hand). Attach the ovals to the wrong side of the lining where the snaps are going to go. Make the cuts through the interfacing and the lining. Without the interfacing the snaps will tear a hole in the lining in a short time.
You do exactly the same on bags that have a flap that attaches to the back and folds over the top of the bag. Attach the female part to the flap and then use the flap folded over the top of the bag to mark where the male part should go. As the snaps will be on the outside of the bag front and on the flap you may not need extra interfacing but still cover the back of the snap with Thermolam using glue.
An alternative to a flap is to add two tabs to the top of the bag that meet with a magnetic snap just inside the top.
This is the tape that you touch together and it sticks to itself with textured surfaces. I tend to use this on money purses and wallets rather than handbags. It comes in a variety of colours. I buy the iron-on sort and iron it into place, but then I stitch it into place as well. Having it anchored into place by ironing is a big help by keeping it exactly in place while you sew.
Very carefully cut out the hole.
Do it a bit at a time and keep checking by putting the face plate against the hole. It’s easy to make the hole too big and impossible to make it smaller again! You can use some seam sealer (like Fraycheck) to seal the edges of the hole.
Place the face plate in the hole and the back plate on the back and push the prongs over the back plate. It’s a good idea to use some glue on the backs of the lock pieces for security. Use some pliers or a flat end screwdriver to push the prongs right down.
Check where you want the twist part to be. Reinforce the back of the area with extra heavy Vilene. (Remembered this time!)
Mark the very centre of where the twist part is going to go. Place the twist part on its side above the mark and draw two marks where the prongs are.
Cut the holes with a seam ripper.
Apply seam sealer to the cuts. Again, only make the holes big enough for the prongs. Put the twist part in the hole and place the ladder back on the back of the fabric.
Push the prongs flat as before.