We should have an outside and an inside to the bag. I suggest you check all your seams now, to make sure they are well sewn, and try out your pockets to make sure they are to your liking. If you need to do any tightening or adjusting, this is the time!
You should have the 4 lining pieces that we cut off the top from last week, plus the two top outer pieces, remaining. We are going to sew in a zipper panel.
Start by pinning your zipper, right side down, against the edge of the right side of the top fabric, as shown below. You will then lay the right side of the lining fabric on top of that. Pin it all together.
In the picture below, there are three layers.
1. Outer fabric, right side up.
2. Zipper, right side down.
3. Lining fabric, right side down.
Using a zipper foot, sew through the three layers, as close to the teeth of the zipper as possible.
Unfold your outer and liner flaps, and it should look like the picture below.
Sew a top stitch just along the edge of the zipper to hold the fabrics down flat.
Repeat the process on the other side of the zipper.
Once you've folded and sewn a top stitch down the other side, your top panel should look like the picture below.
Cut off the end of your zipper.
Now, we will sew it into the inside liner. You should layer the fabrics as follows.
1. The right side UP of the inside liner.
2. The right side DOWN of the inside liner top panel (the one with the zipper in it), which also has the outer fabric on the opposite side.
3. The right side DOWN of the inner lining fabric (from the 3 inches we cut off).
See picture below. Sew through all these layers, stopping about 1/4 inch from the sides. Check to make sure your seams are secure.
Repeat the process on the opposite side. It should look like the picture below.
Next, we will add the 3 inch panels that we cut from the sides. Pin them across the side edges of the zipper panel, also sewing the inside liner of the bag (just like we did previously). Sew across the stitches already made on the sides.
Now, you should pin together the corners of the 3-inch liners, as below. Sew down the side seams.
Your liner should now look like the picture below.
Insert the liner inside the outside of the diaper bag.
You will fold the liner down about 1/4 inch, and the outside fabric down a little farther (because your liner should be a bit shorter than your outer fabric), to match. Pin the mess out of it!
Sew a top stitch all the way around the top edge.
I then reinforced the straps by sewing over the already sewn stitches on the straps. This attaches the straps to both the outside and the inside of the bag, giving it extra strength.
And you're done!
I confess, I'm having a bit of fabric remorse over my choices for this bag. I've been using the bag itself for awhile now, and I am very pleased with the construction of it. I love all the pockets. I love that it is large enough to hold my planner ('cause I'm a dork!). I love that it has a zipper closure so that everyone in my family will not use it as a collective garbage bag for their stuff! BUT, I don't love the fabric itself. I was trying to get out of the box and choose something different than what I'd normally choose. I tend to go for more muted colors and nature-inspired fabrics.... and I think I would like it better if I had continued that. ;) BUT, good for me for trying something new!
Hope you've enjoyed making your diaper bag and it brings you many years of great joy! Let me know if you have any questions or problems! I'd be happy to help!