I'm sure you've encountered zipper tutorials for the bag's closure. There are many ways to make a zip top. You might have seen the zip top tutorial that explains how to make it the way I will explain next. If you scroll down the page you'll see which zip top I'm talking about. But the problem with this system that you usually see, is you can't insert a strap into it, because it will be squished and not pretty to look at; it can't be used as a regular bag with one strap in the sides. But hey, there is a system that gives you the option to do just that!
Some of you might know the way to do the zip top closure without the strap (not really a bag, just a case usually). But for those who don't, I'll start from the beginning. If you already know the basics, skip most of it, and land on the final steps.
(Of course you don't need to do the pattern I did here, because that's an example tutorial I made with a real bag. Make the bag however you want).
1) Prepare the pieces: 2 exterior, 2 lining, and a long enough zipper:

2) Lay down one of the exterior pieces, right side up.
Place the zipper with its right side (the foot) down on the top edge of the exterior piece.
Add the third layer which is one of the lining pieces, its right side down. You basically sandwich the zipper between the two fabric pieces:
Place the zipper with its right side (the foot) down on the top edge of the exterior piece.
Add the third layer which is one of the lining pieces, its right side down. You basically sandwich the zipper between the two fabric pieces:


3) Topstitch the three layers:

4) Now flip the whole deal like in the picture:

And do the same with the other side -
Lay down the other exterior piece right side up, then the bunch that you've already made, right side down (in right side down I mean the zipper's foot should be facing the exterior piece). Again, lay the last piece – the other lining piece – on the other layers, right side down. Here you're sandwiching the zipper again. Pin and sew.
Lay down the other exterior piece right side up, then the bunch that you've already made, right side down (in right side down I mean the zipper's foot should be facing the exterior piece). Again, lay the last piece – the other lining piece – on the other layers, right side down. Here you're sandwiching the zipper again. Pin and sew.

(optional but recommended): Sew both sides of the zipper to make it look nicer and add more strength to it. Careful, you need to sew just those exteriors layers, separately, not all of them:

This is what you've got, all layers together:

5) Make the strap.
6) Now sew around. First, make sure the zipper is open almost all the way, or else you wouldn't be able to turn inside out.
Bring together the couples – exteriors together, and linings together. Both right sides facing each other.
Sew all the way around, leaving a gap in the lining:
6) Now sew around. First, make sure the zipper is open almost all the way, or else you wouldn't be able to turn inside out.
Bring together the couples – exteriors together, and linings together. Both right sides facing each other.
Sew all the way around, leaving a gap in the lining:

BUT! Here is the difference that creates the option to insert a strap. Leave a gap also at the sides of the zipper, where the zipper ends come out. Leave a few cms, little bigger than the strap's width. Make sure both sides are the same:
(optional): Make boxing now.7) Now turn it inside out though the gap in the lining:
This is what you have got:

After turning inside out, you can see the holes in the sides of the zipper. This is where you will insert the strap.
8) Inserting the strap.
Take one end of the strap and insert it into one of the holes in the sides. Pin in place so it won't move.
Note: The strap needs to be pinned only to the outer part of the bag's body, like the way you see in the picture below. Another advice for you, is to place the pin high enough, so you can remove it after sewing, and it won't get stuck inside the fabrics!
8) Inserting the strap.
Take one end of the strap and insert it into one of the holes in the sides. Pin in place so it won't move.
Note: The strap needs to be pinned only to the outer part of the bag's body, like the way you see in the picture below. Another advice for you, is to place the pin high enough, so you can remove it after sewing, and it won't get stuck inside the fabrics!

Reach into the bag through the gap in the lining and turn just the tip with the strap's end inside out again, just a bit, just until you can sew this part. Now sew it horizontally. Make sure the zipper is also tucked in along with the strap:
Repeat for the other side of the strap.9) Turn to its right side again and close the gap in the lining.



















