Round Bottom Bag Tutorial

16 Feb

We can’t all be winners.  But I love y’all, I really do, so I don’t want to send anyone home disappointed.  If you want a little love in your life and you don’t win our Valentine’s Day giveaway, you can still have a bag of your very own.  You just need to pony up for the supplies and get crafty.  To help you out, I’m posting the tutorial for the bag.

2 contrasting fabrics.  A fat quarter of each works great.
About 16″ of 1″ – 2″ ribbon
Matching thread
Yarn, cording or thinner ribbon (about 36″)
Some math skillz (these can be acquired later, trust me)

Start by cutting a circle from the fabric you’ll use for your exterior and one from the lining fabric. I used a blank CD case. If you use the same thing, you can use my measurements and skip all the math bits.

Now for math!
Draw two chords (as marked in the picture above).
Make sure they’re an even number length (such as 4″) so it’s easy to find the center.
Mark the center and draw lines at a right angle from the chords through the circle. It’s most accurate to do this with a protractor, but you can eyeball it.
Where the lines intersect is the center of the circle. Draw a line through that and measure it. That’s your diameter.
Now multiply the diameter by pi (3.14). You have your circumference!

Why do you want all this? It’s so you know how much wide you’ll want the sides of the bag to be. I rounded the circumference up. Meaning, if you’re using the CD case, your circumference is about 17.25″.

Cut a trapezoid out of each of your fabrics. The bottom should be your circumference plus around an inch. I made my top about 2 inches thinner (one inch off each side) than the base.

I made my sides 10″ tall.

Cut two pieces of your wide ribbon so it’s about an inch shorter than 1/2 of the top of the trapezoid. Sound confusing? If you’re using about the same measurements as me, the two pieces will be about 7″ each.

Now start sewing!

Sew your exterior into a loop by sewing the slanted 10″ sides together. Do the same for the lining, but leave a space in the middle so you can turn in out when you’re done. I forgot the first time and just took a seam ripper to it. No biggie.

Pin your ribbon about 2″ down on each side. If necessary, fold over the ends so they don’t fray and sew in place before attaching to the bag. Sew the edges in place, leaving an opening on each short end.

With a long stitch, sew a gathering stitch around the bottom (wider end) of the exterior fabric loop. Gathering up the threads, pin it right sides together to the exterior fabric circle until it lines up.

(this is the lining… I didn’t take a picture of the exterior)

Sew the loop and the circle together. Repeat this process for the lining loop and circle.

Now you have two bags… mostly. Put the exterior bag, turned right side out into the inside out lining bag, matching seams. Right sides will be together.

(sorry for the blur)

Sew around the top of the bag. Flip through the hole in the lining (if you didn’t make it, now’s the time for your seam ripper). Edge stitch around the top of the bag to make it lay nice.

Starting on the left side, pull half of the length of your thin ribbon, yarn or cording through the casing to the right, then back to the left and tie. With the other half, start on the right side, pull the ribbon through the casing to the left, then back to the right and tie. This is my absolute favorite drawstring technique.


Enjoy your bag!

If you end up making this, please send pictures.  And let me know if anything is confusing.  I’ll try to clear it up.



12 Responses to “Round Bottom Bag Tutorial”

  1. bamboo#1 February 22, 2011 at 7:41 am #

    Thanks for posting this tutorial 🙂 It was exactly what I needed, and also fun because of the math bit 😀

    You asked for pictures, so here’s a link to my post about the bag I sewed using this tutorial

    • aprilinautumn February 22, 2011 at 1:49 pm #

      @bamboo#1 I’m glad you enjoyed it! I kind of had fun with the math myself. I always liked geometry.

      • Leah September 17, 2012 at 2:03 pm #

        I’m using your tutorial right now and I’m stuck at the ribbon insertion. I have two tubes… what?

      • aprilinautumn September 17, 2012 at 3:26 pm #

        Do you have two casings? You should have two with a space between them on either side. If that’s it, you’ll put one length of ribbon through both casings, treating the casing like it’s continuous. You’ll put a second length of ribbon through on the opening opposite where the ends of the first ribbon are and pull it through, treating the two casing’s like they’re continuous. It makes the bag cinch up really nicely.

        If I completely misread your comment, email me at 3withoutamap (at) gmail (dot) com and I’ll try to help more. It’s been awhile since I made one!

      • Leah September 17, 2012 at 3:48 pm #

        I just had a lightbulb moment and figured out that the ribbon was for the casing and not the drawstring! Thank you for this tutorial. Mine is all sewn up and ready to use.

      • aprilinautumn September 17, 2012 at 3:50 pm #

        Awesome. So glad it worked out!

  2. Sabrina June 29, 2013 at 6:39 am #

    Thank you for this tutorial. I’m making 3 of them for my wedding in 4 weeks. One thing I found easier was to sew on the casing before sewing the two short edges of the trapezoid together. It just left it easier to sew.


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