Understand paired cuts for half-drop wallpaper.
Why do alternating half-drop phases have different source cut lengths?
Use the matching calculator
Use this decision sequence
- Use the specified finished drop height including trimming.
- Read the selected wallpaper’s repeat and matching phase.
- Round the first phase to a repeat and allow the half-repeat offset in the alternate phase.
- Count complete compatible pairs per roll; treat other remnants separately.
Keep the quantities distinct
| Quantity or assumption | How to use it |
|---|---|
| First phase | Round required height up to a whole repeat. |
| Alternate phase | Include the half-repeat offset before repeat rounding. |
| Unpaired remnant | May need a different feasible cutting schedule. |
Worked comparison
For a 2.5 m drop with a 0.5 m repeat, paired source cuts are 2.5 m and 3.0 m. A 10 m roll fits one complete 5.5 m pair under this conservative layout. Seven drops therefore need 4 rolls.
Check before using the estimate
The paired method is conservative and does not promise minimum roll count for every manufacturer’s matching instructions.
All dimensions, product properties, prices and specifications in this example are illustrative arithmetic inputs. Use the values from your measured plan, selected product data sheet and supplier quote. This guide does not choose construction specifications or certify safety.
Calculation and scope checked 2026-10-04. Methods and scope.
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