Waterproof Zip Bag Tutorial: Part 2

This quick and fun waterproof zip bag makes a perfect treat bag, swimsuit bag, or anything you want to store small items in. Last week, we shared Part 1 of the Waterproof Zip Bag Tutorial from Jess of OklaRoots. Cork and lining pieces were measured, marked, and cut. This week, we’ll show you how Jess assembled the project.

Zipper Tabs


Jess likes to use zipper tabs on the ends of the zipper to reduce bulk in seams. Cut down the zipper to 1.5 inches shorter than the top edge of your bag.

Cut two pieces of cotton two-inches square and lay them wrong sides up. Fold them in half so two of the edges meet, wrong sides together and press.

Open up tabs, fold parallel edges wrong sides together to meet the center fold and press. Both long raw edges should meet in the middle on the back side of the fabric. Refold on the first fold and clip to hold it in place.

To hug zipper tabs on the raw edges of the zipper, insert the zipper end into the folded zipper tab. Clip it in place, and sew along the inner folded edge at an eighth-inch seam allowance with a zipper foot.

Then, cut down the sides of those tabs so that it's the same width as your zipper tape.

Stitching the Zipper


Picture of waterproof zip bag being constructed with a Santa machine applique on front.


Lay the front panel with embroidery right side up. Lay the zipper right side down matching up the midpoints of your outer panel and zipper tape. The zipper is shorter than the top edge of your outer panel. Baste at an eighth of an inch seam allowance.

Place your exterior piece with your embroidery right side up. Take your lining piece and lay it right side down (woven side), matching up mid-points. Clip in place. Sew at a quarter-inch seam allowance.

Flip your exterior and lining panels so they are wrong sides together. If you're using quilting cotton, press along this top seam by the zipper to hold it all in place. Since this project uses cork and waterproof vinyl, finger press to get the top as straight as possible.

Top stitch along this top folded edge at an eighth-inch seam allowance along the zipper. There will be about three-quarters of an inch on both zipper ends where you don't top stitch.

Do the same to attach the back exterior and back lining to the zipper. Top stitch along the zipper.

Open the zipper, fold exterior fabrics right sides together, and fold your linings right sides together as well. Clip along all edges to keep everything lined up.

Sewing the Bag

On the exterior side you're going to sew everything at a three-eighths inch seam allowance along the side and the bottom. Do not sew box corners. Backstitch well at every edge.

At the seam between the lining and the exterior fabric, sew a three-eighths inch seam allowance or as close as you can get to the edge of the zipper tab without actually sewing over it. The goal is to not sew that fabric zipper tab. At the lining side, increase your seam allowance to a half-inch.

Do a full half-inch seam allowance on the bottom and then, on the other side, decrease it to three-eighths inch. Backstitch well at all corners.

On the short bottom edge of your lining panel, mark a four-inch opening. Use a half-inch seam allowance, but don't sew corners or between the marks. 

Trim down the seam allowance just a bit, except for the opening flap.

Boxing Corners


Starting with the exterior panel, pull open the corner edges so that the seams from the bottom and the sides come together. Rotate them in opposite directions, the bottom seam is going to go to the right and the side seam is going to go to the left, so that they kind of give each other a little hug.

Straighten out raw edges and clip. Do the same to the other exterior corner. Make sure you fold your bottom seam in the same direction that you did on that first corner. Sew corner edges with a three-eighths inch seam allowance.

Do the same thing for the lining. Sew at a half-inch seam allowance.

Put your hand in through the bottom opening and push the exterior and the lining through that hole. Put your hand into the back of the exterior and push out corners.

Close up the turning hole in the lining either by hand or by machine as close to edge as possible. Insert lining into the exterior and push the corners of your lining all the way down to the corners of your exterior. Push out corners by the zipper.

Picture of waterproof zip bag with Santa Buddy machine applique design on front.


This makes an adorable gift bag to fill with cookies or maybe a bubble bath set or a hot cocoa mix and mug.  Since it's waterproof, it would work great for wet swimsuits on the go.  You can also add D-rings to the sides and make it a cookie cross body.

This is just a beautiful way to gift something. It's like a little hug that you're sending in a little bag.

It would also be fun to make an Easter treat bag using Bunny Buddies or Eggsquisite Jewels, or a bag for wet swim suits using Merry Mermaids or Sea Buddies

I want to thank Jess for letting us share her project with you.  You can see Jess' full video here.

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  • Bonnie Welsh - January 26, 2021

    Karen—Thank you for your kind words! Welcome to our group. I’m glad you found me too. =)

  • KAREN NORMAN - January 26, 2021

    Just darling,,,,,,, so glad I found you and your beautiful drsigns. Your ceeativity is amazing.

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