Free Diagonal Strip Quilt Pattern

Pattern Description:

The Diagonal Strip Quilt is a fun and modern design that looks complex but comes together surprisingly quickly using the tube method. 

One of the main advantages of this pattern is that you can use pre-cut jelly rolls, fabric strips cut at 2 ½” width, or cut your own from stash fabrics. 

The quilt’s bold diagonal lines give it a fresh, dynamic look, making it an excellent choice for baby quilts, throws, or even twin-size bed coverings.

This tutorial provides detailed instructions, fabric requirements for different sizes, and helpful tips for managing bias edges so that your finished quilt looks neat and professional.

Materials Needed & Measurements:

• Fabric Strips
  
  • Six strips measuring 2 ½” x Width of Fabric (WOF) are required to make one tube.
    
  • Jelly rolls are ideal since they are already pre-cut to the correct width.
    
  • If using fat quarters, cut 2 ½” x 21″ half strips. In this case, you will need to double the number of strip sets to achieve the same results.
    
• Thread & Seam Allowance
  
  • Use a high-quality thread for durability.
    
  • All seams are sewn with a ¼” seam allowance.
    
• Ruler
  
  • A large square ruler with a 45-degree line is necessary for accurate diagonal cutting.
    
  • The ruler must be larger than your strip tube. A 9 ½” square ruler is recommended.
    
• Other Essentials
  
  • Rotary cutter and cutting mat.
    
  • Iron and pressing board.
    
  • Pins or clips for alignment.
    
  • Sewing machine with straight stitch capability.
    

Quilt Sizes and Block Yield

Each tube produces six diagonal triangle blocks. After pressing and trimming, blocks measure slightly under 8 ¼”, but calculations for quilt sizes are based on a 7 ¾” finished block size for consistency.

Quilt Size	Dimensions	Number of Blocks	Layout (Across × Down)	Strips Needed	Tubes Required
Baby	38 ½” x 46 ½”	30	5 × 6	30	5
Crib	46 ½” x 54 ½”	42	6 × 7	42	7
Small Throw	54 ½” x 69 ½”	63	7 × 9	66	11
Large Throw	62″ x 77 ½”	80	8 × 10	84	14
Twin	69 ½” x 85″	99	9 × 11	102	17

Step-by-Step Tutorial for Making the Diagonal Strip Quilt Pattern:

Step 1: Preparing the Strip Tube

• Gather Fabric Strips
  • Select six strips measuring 2 ½” x WOF. Use coordinating colors for a cohesive look or mix scrappy fabrics for a playful style.
• Create Two Strip Sets
  • Sew three strips together lengthwise, right sides facing.
  • Repeat with the remaining three strips.
  • Press all seams open to reduce bulk and help maintain straight edges.
• Join into a Tube
  • Place the two strip sets right sides together, carefully aligning the edges.
  • Sew along both long sides, enclosing the strips into a tube shape.
• Pro Tip: Pressing seams open in the strip sets is important because it keeps the tube flat and prevents distortion later when cutting on the bias.

Step 2: Cutting the Tube Diagonally

This stage creates the diagonal strip blocks that make up the quilt design.

• Position the Ruler
  • Place your tube on the cutting mat.
  • Align the 45-degree line of the square ruler with the bottom stitch line of the tube.
  • Cut along the right side of the ruler (left side if you are left-handed).
• First Block Cut
  • Move the ruler up to the top row of stitches, again lining up the 45-degree angle.
  • Position the ruler’s corner on the freshly cut edge.
  • Cut along the ruler edge to form the first diagonal triangle block.
• Continue Cutting
  • Alternate between aligning the ruler with the bottom seam line and the top seam line.
  • Each new cut begins where the last cut ended.
  • Continue until the tube is fully cut.
• Each completed tube yields six blocks.

Step 3: Handling and Pressing the Blocks

Since the blocks are cut on the bias grain, the edges are stretchy and prone to distortion. Careful handling is essential.

• Open the Blocks
  • Gently separate the cut triangles to reveal the diagonal design.
• Press Carefully
  • Use an up-and-down pressing motion. Avoid sliding the iron across the fabric.
  • Press seams open or to the side, depending on your preference.
  • Handle blocks minimally to avoid stretching.

Step 4: Assembling the Quilt

Once you have made the desired number of tubes and blocks, you are ready to assemble the quilt top.

• Layout Design
  • Arrange the blocks on a design wall or floor.
  • Experiment with different orientations to create movement in the quilt.
  • Many quilters choose to vary the strip order in each tube for added interest.
• Sew Rows Together
  • Join blocks in rows, right sides together.
  • Pin seams where they meet for accuracy.
  • Sew with a ¼” seam allowance, being mindful of the bias edges.
• Join Rows
  • Sew rows together to complete the quilt top.
  • Don’t worry if some seams don’t align perfectly; the diagonal pattern disguises small imperfections.

Step 5: Securing the Quilt Top

The quilt top has many bias edges, making it susceptible to stretching.

• Stay Stitching: Sew around the perimeter of the quilt top using a regular stitch length.
• This stabilizes the edges and keeps the quilt from distorting during basting, quilting, and binding.
• The pattern designer recommends not exceeding a twin size because handling larger tops with so many bias cuts becomes challenging.

Step 6: Finishing the Quilt

• Basting
  • Layer the quilt top, batting, and backing.
  • Baste with safety pins, spray adhesive, or long basting stitches.
• Quilting
  • Straight-line quilting works beautifully with the diagonal design.
  • You can stitch in the ditch along the strip seams or quilt parallel diagonal lines for added texture.
• Binding
  • Finish with binding strips, preferably cut on the bias for flexibility around edges.
  • Hand-stitch or machine-stitch the binding to complete the quilt.

Tips for Success

• Use starch or fabric stabilizer to reduce stretch when cutting and handling bias edges.
• Chain piecing strip sets speeds up the process.
• A design wall is helpful for previewing the block layout before sewing rows together.
• Scrappy fabrics create a fun, eclectic look, while coordinated strips offer a more polished appearance.