4 Piece Set Quilt Half Hexagons & Hexagons w/ Seam Allowance & Guideline Holes 4 Piece Set Half Hexagon and matching Hexagons. Half Hexagon sizes are 4" & 5" along the bottom seam allowance lines. Hexagon sizes are 4" & 5" top to bottom of the seam allowance lines. Use this matching set to make many patterns. This set has the Guide Line Holes. 1/8" Thick Acrylic Markings are laser engraved for long lasting use. This set does have the seam allowance.