Riley Blake Rainbow Tiles - Downloadable PDF

Riley Blake Rainbow Tiles Quilt Pattern – Free Downloadable PDF for Beginners

The Riley Blake Rainbow Tiles pattern, designed by RBDDesigners for Riley Blake Designs, is a free downloadable PDF quilting pattern that produces a stunning 88" x 88" finished quilt — a generous, full-size throw or bed quilt bursting with color. This beginner-friendly project is built entirely from Half Square Triangle (HST) blocks, one of the most foundational and versatile units in quilting. The result is a vibrant, tile-like arrangement of rainbow hues set against a crisp white background, making it an ideal project for quilters who are just developing their skills while still wanting a visually impressive finished piece.

What Is Being Made

This pattern creates a single large quilt measuring 88 inches by 88 inches, constructed from 400 Half Square Triangle blocks arranged in a 20-row by 20-block grid. Each finished HST measures 4" x 4", and together they form a bold, mosaic-style "rainbow tiles" design. The quilt is completed with a border that frames the pieced center, adding structure and a polished finish. The overall effect is a sweeping gradient of rainbow colors — reds, oranges, yellows, greens, teals, blues, purples, and pinks — set against a neutral white background that allows each color to shine.

Techniques Used

• Half Square Triangle (HST) construction: The core technique of this pattern. Each HST is made by pairing a background square with a colored square, drawing a diagonal line on the back of the background square, sewing a quarter-inch seam on both sides of the line, and cutting along the line to yield two HST units from a single pair of squares. This is one of the most widely used techniques in patchwork quilting.
• Pressing and trimming: Each HST is pressed toward the colored fabric and then trimmed to 4½" x 4½" to ensure accuracy and consistency across all 400 blocks.
• Row construction: HST blocks are arranged and sewn together into 20 rows of 20 blocks. Rows are pressed in alternating directions to reduce bulk at seam intersections — a standard quilting technique that helps seams nest together neatly.
• Border attachment: Nine border strips are joined end to end and then cut into two 80½" segments (for the sides) and two 88½" segments (for the top and bottom), which are sewn on in sequence to complete the quilt top.
• Right Sides Together (RST) sewing: All piecing is done with fabric right sides facing each other, a standard quilting convention referenced throughout the pattern.

Stitches and Sewing Details

• Quarter-inch seam allowance is used throughout — the standard seam allowance for quilting, already included in all cutting measurements.
• Straight-stitch sewing is used for all piecing, both for the diagonal HST construction lines and for joining blocks, rows, and border strips.
• The diagonal stitching lines on the HST units are sewn ¼" from both sides of the marked center diagonal, a precise and efficient method for producing two mirror-image triangles per fabric pair.

Materials – Fabric Requirements

This pattern calls exclusively for Riley Blake Designs C120 Solid fabric in a carefully curated rainbow palette. A total of 25 coordinating solid colors are used, each requiring just 1/6 yard, making this an excellent pattern for using up small cuts or building a rainbow solid collection. The full color list includes:

• Reds and pinks: C120 Cayenne, C120 Riley Red, C120 Rouge, C120 Riley Hot Pink, C120 Riley Raspberry (also used for the border), C120 Riley Coral, C120 Rose
• Oranges and yellows: C120 Autumn, C120 Riley Orange, C120 Daisy, C120 Riley Yellow, C120 Sunshine
• Greens: C120 Pear, C120 Riley Lime, C120 Leaf, C120 Treetop