1. Assemble the bench according to Ikea’s instructions.
2. Use the bread knife, yardstick, and Sharpie to trim the foam to 14 by 62.5 inches.
3. Cut the fabric pieces using the yardstick, Sharpie, and scissors. You’ll need . . .
• For the cushion: (1) 16 by 64.5 inches [Piece A], (2) four by 64.5 inches [Piece B], and (2) four by 16 inches [Piece C]
• For the top bench lip: (2) two by 64.5 inches [Piece D] and (2) two by 16 inches [Piece E]
• For the bench sides: (2) four by 60 inches [Piece F] and (2) four by 10 inches [Piece G]
• For the outside legs: (4) six by 17 inches [Piece H]
• For the inside legs: (4) six by 14 inches [Piece I]
4. Cut the white fabric into two-inch-wide strips. Fold a strip around the piping cord, and loosely pin in place. Sew along the cord (as close as you can without sewing on the cord). Continue covering the cord and sewing until all the cord is covered.
5. Fold a one-inch border (like a faux hem) around all sides of the cushion pieces (Pieces A, B, C), and iron in place.
6. Pin the piping around the border of the A piece, so that the cord of the piping faces the front of the fabric and the seam and tail of the piping will be on the backside of the fabric. At the corners, cut a slit in the tail of the piping, so the cord can make a sharp bend. Sew in place, sewing as close as you can to the piping cord without sewing on the cord itself.
7. Sew the short sides of the B pieces and C pieces together with a one-inch border, so that the front side of the fabric faces itself and the seams will be on the backside of the fabric.
8. Pin the B and C sides onto the A piece with a one-inch border, so that the front side of the fabric faces itself and the seams will be on the backside of the fabric. Sew in place, sewing as close as you can to the piping cord without sewing on the cord itself.
9. Flip the pieces inside out and cover the foam cushion. Use pins to stretch the fabric as tightly as possible on the cushion. Flip the cushion upside down and hot glue the fabric in place on the underside of the cushion. Let the glue cool, and remove the pins. Set the cushion aside.