If I'm following this correctly, 4 pieces of fabric each 1.5" x 42", sewn together the long way. Using a quarter inch seam allowance means the pieces finish at 1", so 4" finished, but your sewn size of the four strips should be 4.5, not 5" -- but not 4" either
Good luck!
1.25" (one seam, one raw edge)
1" (two seams)
1" (two seams)
1.25" (one seam)