A little bit of patchwork is all you need to turn a basic sweatshirt into boutique style fashion! This DIY mini quilt block sweatshirt is the perfect blend of cozy and cute. Use my tutorial to see how you can make one for yourself! It’s a fun project you can complete in an afternoon.
This quilt block sweatshirt leans into the grandma core aesthetic that’s so popular right now. This sweatshirt DIY takes traditional quilt blocks and adds them to a modern wardrobe staple. I’ve got a tutorial for you below.
The design is really pretty simple. Just three mini patchwork quilt blocks appliqued across a basic sweatshirt with the neck cut out.
Each quilt block measures just 3” x 3”. You can use your fabric scraps or even a charm square pack to make the three small blocks for this shirt.
If you’ve never assembled a quilt block before, be warned. It just might become your new obsession. It’s so much fun seeing the squares of fabric come together to make a design.
The simple quilt block designs look best when made from two color groups. On the sweatshirt I made, two of the quilt blocks have a blue/dusty rose color palette, and one has a blue/beige palette.
Once you make your mini quilt blocks it’s easy to applique them to the sweatshirt. Or if sweatshirts aren’t your thing, they would also be adorable on a canvas tote bag. (And of course now that I’ve written those words, I’m thinking I may need to sew up a few more quilt blocks to make a new bag for myself.)
Supplies
Quilting cotton – fat quarters (or large scraps)
Fusible webbing – ¼ yard or large scraps
Accuracy is important when sewing patchwork. You need accurate cuts and seam allowances in order for all the pieces to line up correctly to make the design. You’ll need to use a rotary cutter/ruler/mat for your fabric cuts.
All seam allowances are ¼”. RST = Right Sides Together
Cut the Fabrics
Each patchwork block is made up of two main colors. Let’s call them Color A and Color B.
The cutting instructions below are for 1 block. For my sweatshirt, I made 3 blocks – 2 that used a Blue/Dusty Rose palette, and 1 that used a Blue/Beige palette.
For each mini quilt block you’ll need:
3” squares – 1 from Color A and 1 from Color B
1.5” squares – 1 from Color A and 3 from Color B
3.5” square – 1 from Color B
Create the Half Square Triangles
There are many ways to create half square triangles. Since each patchwork design uses 4 half square triangles, I used the 4-at-a-time method.
Place the 2 3” squares RST. (One square is Color A, the other is Color B.)
Sew around all sides with a ¼” seam allowance.
Cut diagonally from corner to corner.
Press each piece open. Now you have 4 little half square triangles.
Trim each half square triangle down to 1.5”, making sure to keep that diagonal line running from corner to corner.
A small acrylic ruler with 45 degree angle markings will be your best friend for this step.
You’ve just made 4 half square triangles!
Assemble the Mini Quilt Block
Now that you’ve got your half square triangles, it’s time to assemble the patchwork design.
Lay your fabric pieces out like this.
Piece the squares together in rows.
Then, sew the rows together, making sure to match seams.
You’ve made a mini quilt block!
You’ll notice that the points of the triangles don’t come all the way to the outer edge of the block. That’s fine, and it’s actually the way it’s supposed to be.
Make the Quilt Block Applique
Once you’ve got your mini quilt block, it’s easy to turn it into a little applique that you can stitch down to a sweatshirt.
Take that last square, the 3 ½” square from Color B, and cut a slit in the center. Length and placement aren’t super important, as long as it stays in the center portion of the square.
Place that square on top of the mini quilt block, RST.
Sew around all 4 sides.
Clip corners, then turn right side out through the hole you cut in the middle of the square.
Follow manufacturer’s instructions to iron a square of fusible webbing to the back of the mini quilt block.
Assemble the Quilt Block Sweatshirt
All that’s left now is to attach your patchwork squares to your sweatshirt.
Peel off the paper backing from the fusible webbing and arrange your mini quilt blocks on the sweatshirt.
I used 3 blocks for my sweatshirt. Before I arranged them, I cut the ribbed neck out from the sweatshirt to create a larger looser neckline. Then I arranged the 3 blocks in a row, roughly 4 ¼” down from the lowest point of the neckline.
Follow manufacturer’s instructions to fuse the mini quilt blocks in place.
Top stitch around each block to secure.
Your mini quilt block sweatshirt is finished!
If you love this mini quilt block sweatshirt from Anne, you are sure to love these sewing tutorials as well:
Upcycled Sweatshirt Slouch Bag Sewing Tutorial
Tea Towel Apron Sewing Tutorial
Spring Flower Tote Bag – Free Sewing Pattern
Latest posts by Anne Weaver (see all)
- Slouchy Market Bag with Veggie Prints – Free Pattern - May 14, 2026
- Flex Frame DIY Glasses Case Sewing Tutorial - April 18, 2026
- Scallop Zipper Pouch – Free Sewing Pattern - March 10, 2026
[…] might recognize some of the scraps in there from the mini quilt block applique sweatshirt I made a few months ago. I never throw away a scrap. You never know when it’ll make the perfect […]