How to Make Scrunch Bikini Bottoms (Without Buying a Pattern!)

I’ve gotten quite a few requests on how to make scrunch bikini bottoms, and I thought I’d add in some notes for how to make them without having to buy any additional patterns!

In this tutorial, I am using an existing bikini bottoms pattern I made, found here, and I’m going to be modifying it so that when I insert the scrunch detail, it will remain the exact same shape.

If you make the mistake of adding a scrunch without modifying the pattern, it will ultimately make the bottoms too low in the back. By modifying your pattern first, you can prevent this from happening!

If you’d prefer to watch the video instructions for this, see below. Otherwise, keep reading!

  1. Get your existing pattern ready. I’m using the pattern for the Ranger bottoms. Trace an existing pair of bikini bottoms if you don’t have a pattern. We will be leaving the front piece alone, only making modifications to the back piece.
  2. Trace a copy of your back piece onto pattern paper. Make an exact copy, and cut it out.
  3. Once you have your “clone” back piece, draw a horizontal line about 4″ up from the gusset area. We will be using this line to lengthen the pattern. If you’ve ever sewn a dress or skirt, you may have noticed that the patterns include a similar horizontal line that says “lengthen or shorten here”. This line seems to be randomly placed and it is usually never at the very bottom of the garment like you might think. Having the line a little further up allows the garment to maintain its same general shape.
  4. Take your clone piece with the line on it, and cut it along the horizontal line.
  5. Getting your pattern paper out, place the pieces of the clone piece together. Depending on how much scrunch you want, you will space out the pieces to lengthen the pattern. Since I wanted a minimal scrunch, I spaced out about 2″. That means that the extra 2″ of fabric will be scrunch up in the bottoms. If you did 5″, those 5″ would be scrunched, making it more of an intense scrunch. Since the pattern piece for bottoms is typically 8-10″ tall, the more inches you spread your pattern the more intense the scrunch.
  6. Once you’re happy with your decided “scrunch level”, tape the clone pieces down in their place. Trace the pieces one more time, using french curves if needed in order to maintain the same slope and shape as the original back bottoms. Cut your new back pattern out- we’ll call it the scrunch back piece from now on.
  7. So now you should have 3 pattern pieces- the front, back, and scrunch back. As with normal bottoms, we will now cut 2 of the front piece. We will cut 1 of the back piece and 1 of the scrunch back piece. Remember that the scrunch back will be the outside-facing fabric, and the regular back piece will be your lining.
  8. Once you have all your pieces, we will finally add the scrunch! The first step is measuring your elastic. As previously mentioned, the back of bottoms pieces typically is around 8-10″. For a size medium, it’s 9″. You want your scrunch bottoms to maintain the same shape as regular bottoms, so you will cut your braided elastic to fit the height of your bottoms. If you’re unsure of this measurement, simply take your regular back piece and cut your elastic to fit it. Also- in most of my tutorials I am using rubber, swimwear elastic. This is one of the few instances where I am purposely NOT. Rubber elastic will tear when it is stretched and sewn in the manner that we will be sewing. If you don’t want to use braided elastic, another option is clear elastic.
  9. To sew the scrunch, first draw a line down the middle of your scrunch back piece. Take some pins and pin down one edge of the elastic on to the top and the end to the bottom. Sew down to secure.
  10. Now you’ll notice that if you stretch the elastic, you will be able to sew it down onto the bottoms along the middle line that we drew. Sew it down, and remember to continue stretching the elastic until you sew all the way down. Once you release it, you’ll notice it scrunches when the elastic rebounds.
  11. Double check to make sure your scrunch back piece and your regular back piece line up!
  12. Finish your bottoms as you would regularly. You can watch my method for sewing bikini bottoms below.

By using this method, the scrunch detail can be added to any pattern for bikini bottoms you have.

Thank you for taking the time to read or watch this tutorial!

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