Straight match, strip by strip
How a repeating pattern lines up when every drop starts on the same phase.
Straight match means each strip starts at the same point in the repeat. Horizontal motifs line up across the wall. The cut length is the wall height plus your allowance, rounded up to a whole number of repeats so the next strip can start cleanly.
On a 400 cm × 240 cm wall, a 53 cm roll, a 64 cm repeat, and 10 cm of allowance: the raw drop is 250 cm, which rounds to 4 × 64 = 256 cm. The wall needs 8 strips because 400 ÷ 53 is 7.55. A 10.05 m roll holds 3 strips. You buy 3 rolls. The full worked figures are on worked example.
The planner does not overlap strips. If your paper says to double-cut a seam, add that waste yourself. The last strip is narrower: 400 − 7×53 = 29 cm.
Set the match to straight on cutting plan and move the window. The strip is still cut full length; the opening is area you trim out of that strip.