DIY Triangle Bikini: Create Your Own Swimsuit with a T-Shirt!

DIY Triangle Bikini: Create Your Own Swimsuit with a T-Shirt!

Table of Contents:

  1. Introduction
  2. Bikini Sewing Tutorial: Part 1
    • Materials Needed
    • Making the Bikini Pattern
    • Cutting the Pattern Pieces
  3. Bikini Sewing Tutorial: Part 2
    • Sewing the Bikini Top
    • Attaching the Neck Ties
    • Sewing the Channel for the Drawstring
  4. Conclusion

Bikini Sewing Tutorial: Part 2

Today's tutorial is the second part of our bikini sewing tutorial. In this tutorial, we will be focusing on making the pattern for the bikini top and sewing the pattern pieces together. If you haven't checked out the first part of the tutorial, you can find the link in the description below. The first part covered the basics of making a bikini bottom, and in this tutorial, we will complete the set by making a matching bikini top using a Nike t-shirt. So let's get started!

Materials Needed

Before we begin, let's gather all the materials we will need for this project. Make sure you have a measuring tape or ruler, a pencil, scissors or a rotary cutter, a piece of paper (preferably sketch paper), and the remaining Nike t-shirt from the first tutorial. If you don't have a straight ruler, a measuring tape can be used as a substitute. Additionally, you may want to have pins or a safety pin on hand, as well as a loop turner for threading the drawstring.

Making the Bikini Pattern

To make the pattern for the bikini top, we will start by folding the paper in half vertically, ensuring the edges meet to create an accurate fold. Unfold the paper and you will have a defined center line. This center line will be the reference point for our pattern. Using your ruler or measuring tape, mark a point 7.5 inches from the center line. Fold the paper at this mark, creating a half of 7.5 inches. Open the paper and mark the full 7.5 inches from left to right. This is the width of our pattern.

Next, measure 6 inches down from the center line and mark it. From the top of this line, measure a half inch inwards and mark it. Repeat this step from the bottom of the line. Connect these points to the center line, forming a triangular shape. Now, mark half-inch intervals on both sides of the triangle. Finally, connect the top corners of the triangle to the outer half-inch marks.

To create the desired curve, you can either use a curved ruler or freehand the curve. Fold the paper outward and cut along the line we have just drawn. When you open it up, you should have a square-shaped pattern with a slight curve at the bottom.

Cutting the Pattern Pieces

Now that we have our pattern, it's time to cut out our fabric pieces. Lay the t-shirt flat, ensuring it is even on the bottom, and smooth it out. Place the pattern on top of the t-shirt, making sure to cover any desired patterns or designs. Cut around the pattern, creating two pieces for the bikini top. Since we are not doubling the fabric, we will only need one side for each piece.

For the bikini straps, we will also be using the t-shirt fabric. Using your ruler, create an even line across the desired width of the straps. Cut along this line, ensuring the fabric stays even. This will give us the straps for our bikini top.

To complete the pattern, fold the top edge of each fabric piece inward by a quarter inch. You can press it down with an iron to create a sharp edge for easier sewing. Next, fold the side flaps inward and press them down as well. This will create a narrower fabric piece. Finally, fold the top part of each piece to create a channel for the drawstring.

Sewing the Bikini Top

Now that we have prepared our fabric pieces, it's time to sew them together. Take one of the fabric pieces and fold it in half, right sides together. Sew along the sides, leaving the top part of the flap open. Repeat this step for the second fabric piece.

Next, take both fabric pieces and match them, right sides together. Sew along the top edge, leaving a small opening at the center. This opening will be used to insert the drawstring later on. Once sewn, flip the fabric right-side out.

Attaching the Neck Ties

To attach the neck ties, fold the long straps in half and sew across one end, securing the two halves together. Use a loop turner or a safety pin to flip the strap right-side out. Repeat this step for the second neck tie strap. Once both straps are ready, attach them to the edges of the bikini top, ensuring they are evenly spaced.

Sewing the Channel for the Drawstring

Lastly, sew a straight line across the top flap, securing the drawstring channel in place. Make sure to leave the center opening to insert the drawstring later. And with that, our bikini top is complete!


Congratulations on completing your homemade bikini top! With just a few simple steps and some basic materials, you have created a custom piece that fits your style and preferences. Feel free to experiment with different fabric choices, strap lengths, and design modifications to make it truly unique. Now you can hit the beach in style with your one-of-a-kind bikini set!


  1. Learn how to make a pattern for a bikini top using basic materials.
  2. Sew the pattern pieces together to create a custom-fit bikini top.
  3. Attach necktie straps for added comfort and style.
  4. Create a drawstring channel for an adjustable fit.
  5. Personalize your bikini top with different fabric choices and design modifications.


Q: Can I use different fabric for my bikini top? A: Yes, you can use any fabric that suits your preferences. Just make sure it is suitable for swimwear.

Q: Can I adjust the strap length for a better fit? A: Absolutely! Feel free to modify the strap length to achieve the desired fit and comfort.

Q: Can I add padding to the bikini top? A: Yes, you can add padding by sewing in removable or sewn-in cups to enhance support and shape.

Q: Can I make different sizes using this tutorial? A: Yes, you can adjust the pattern size to fit your measurements. Simply extend or reduce the width and length accordingly.

Q: Is this tutorial suitable for beginners? A: Yes, this tutorial is beginner-friendly and covers all the necessary steps in detail. Just take your time and follow the instructions carefully.

Q: How long does it take to complete the bikini top? A: The time needed may vary, but on average, it can take a few hours to complete the entire sewing process, including cutting and sewing the fabric pieces.

Remember, practice makes perfect, so don't be discouraged if your first attempt doesn't turn out exactly as expected. Enjoy the process, experiment with different techniques, and have fun creating your own unique swimwear!

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