Repeat and Seam
A student is designing a repeating furnishing fabric for a 90 cm wide loom. The motif is built inside a 12 cm × 12 cm square. The first trial uses a straight repeat, but when the fabric is folded at the seam the diagonal stems break: the motif is cut at the right edge and does not continue on the left edge. The student switches to a half-drop repeat with a 6 cm vertical offset. The screen is 15 cm × 15 cm, and a 1.5 cm seam allowance is required on both selvedges. The design must also work across a 90 cm width with no motif cut by the seam. The student wants to know whether to change the repeat, resize the motif, or redraw the edges, and how many repeats will fit.
1. Explain why the straight repeat broke at the seam and why half-drop alone may not solve it.
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A straight repeat tiles by placing identical squares side by side, so the right edge of one unit must continue the left edge of the next. If the motif is simply cut at the right edge and does not reappear on the left, the stems stop at the seam and restart in the wrong place. Half-drop changes the vertical relationship between alternating columns by 6 cm, which can make a break less obvious by staggering it, but it does not create continuity by itself. The seam still cuts through whatever crosses the repeat boundary. Half-drop can even make the break more noticeable if the offset places a stem end against a blank area. The real choice is either to design an edge-to-edge repeat, drawing the motif across the boundary and duplicating the crossing part on the opposite edge, or to place the seam in a deliberate negative-space band. Resizing alone does not fix a non-continuous motif.
2. Calculate a repeat layout for the 90 cm width with 1.5 cm seam allowances, and recommend a solution.
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Usable width = 90 − (2 × 1.5) = 87 cm. A 12 cm repeat gives 87/12 = 7.25, so seven repeats use 84 cm and leave 6 cm; that 6 cm is 3 cm per side, of which 1.5 cm is seam allowance and 1.5 cm is spare. That is workable only if the motif has a 1.5 cm plain edge, which would create a 3 cm gap across the seam. A cleaner solution is to adjust the repeat to divide 87 exactly: 87/7 = 12.43 cm. The motif grows by only 3.6%, from 12 to 12.43 cm, and still fits the 15 cm screen with 1.28 cm margins. Use seven repeats across the 90 cm width: 7 × 12.43 = 87 cm, plus 1.5 cm seam allowance at each selvedge. For half-drop, offset alternate repeats by 12.43/2 = 6.21 cm. This is preferable to eight repeats of 10.875 cm, which would shrink the motif by about 9.4% and make it weaker at furnishing scale.
3. Describe how to prepare the screen and registration marks for the chosen repeat, including seam allowance.
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Prepare the 15 × 15 cm screen with a 12.43 cm square repeat boundary and at least 1 cm of clear border for registration. Redraw the motif so that any stem crossing the right boundary re-enters at the same height on the left boundary; test this by tracing the square, shifting it one repeat width, and checking alignment. Mark the half-drop offset of 6.21 cm on the screen frame and on the print table so alternate rows are placed consistently. Print a test length of at least three repeats, fold the fabric at the 1.5 cm seam line, and check whether the pattern matches across the fold; if it does not, correct the edge drawing before printing the full 90 cm width. Keep registration marks outside the repeat area so they do not print on the cloth. The seam allowance should be marked on the fabric, not printed as part of the motif; the first 1.5 cm from each selvedge stays plain or carries a deliberate border.