VectorPaint zipper illustrations: check staggered teeth, open/closed regions and slider occlusion

English translation of the Chinese original, translated on 2026-11-04. Original publication dates, attribution, code and version notes are retained.

A zipper combines repeated elements with an open-to-closed transition. Draw an original simplified illustration by arranging teeth before slider occlusion. This practises duplication and local continuity, without validating real tooth engagement, sewing, material strength or manufacturing dimensions.

Define open and closed regions first

Create a 700 by 1000 pixel portrait canvas, with tapes separated above, approaching the centre below and a slider near the transition. Begin with two tape placeholders and no teeth, checking opening direction and composition. A legend can define upper as open and lower as engaged, preventing unexplained directional changes within one illustration. Keep principal tape widths similar; slight curvature is acceptable but is not a model of real zipper loading. Leave slider/pull space and bottom clearance. Save this structural baseline before adding teeth so repeated details cannot conceal problems in the underlying open/closed relationship.

Build one tooth and inspect repeat spacing

Use a small rectangle or low-node shape as a source tooth. Place four or five on the left tape with consistent spacing and visible length. Copying preserves appearance but does not guarantee equal spacing along an arbitrary curve, so compare sections against the tape edge. Start the right side at matching size rather than abruptly thicker teeth. Test this small repeat before duplicating dozens. Establish clear attachment to the tape, not floating fragments. Keep tapes, teeth and references in separate layers and name teeth by side or region so omitted/duplicated objects under the slider can be identified without random selection.

Use staggering to suggest the closed region

In the lower region, stagger left and right teeth and identify each source instead of overlapping both rows into one heavy line. This simplified rhythm suggests engagement without claiming that rectangles mechanically interlock. Read origins down the centre and inspect sudden spacing changes. If the result resembles isolated beads, repair tooth-to-tape attachment before adding highlights. Temporary side colours can aid inspection, then be restored. Cropping may make left/right tooth counts unequal, but counts and origins within the visible region should still be explicable.

Arrange open-region teeth along their tapes

Arrange upper teeth along their respective inner tape edges at a visual size similar to the lower section. Manually adjust a few angles near curves instead of distorting an entire row and changing tooth sizes. Reserve the transition for slider occlusion rather than forcing every line through the centre. Hide the slider to inspect continuity, then restore it to inspect coverage. If covered teeth are omitted, retain enough source references to avoid exposing an undrawn void when moving the slider. Ordinary objects do not generate following teeth automatically; maintain the actual visible range item by item.

Keep slider and pull occlusion explicit

Draw a simple closed slider shape in front of the transition and a small loop or elongated pull. Check that it covers the intended teeth rather than merging both tapes into an unidentifiable block. Give the pull a clear attachment and any required stacking relationship instead of leaving it floating nearby. Lighting is supplementary: hide light/dark details to inspect silhouettes. Use original generic geometry without real branding that would imply a product structure drawing. Slider length follows this composition rather than a universal production dimension; physical operation and strength need actual mechanical and material validation.

Move the slider to test revealed continuity

Move the slider slightly upward in a copy solely to inspect tapes and teeth revealed underneath. Moving the slider alone does not simulate opening or closing: the open/closed regions would also need redrawing. For a second state, first list which teeth and tape edges change, then make another static diagram. Ordinary shapes do not automatically deform and engage. Restore the baseline after testing, remove unnecessary copies and check that replacement teeth have not doubled either row. This tests illustration maintenance and does not turn two images into working mechanics or interactive animation.

Check whether repeated details survive output

Save the source and inspect centre teeth, upper opening and pull attachment at the intended export size. Remove tiny highlights or reduce visible tooth count in a separately saved simplified version when necessary, preserving rhythm instead of forcing every detail into a small image. Check edges on light and dark backgrounds; transparency settings do not automatically remove backing objects behind tapes. Name simplified illustration, state and revision and reopen the actual shared image to exclude temporary side colours or structural references. Real product instructions require fresh comparison with the physical item and wording; this exercise does not validate every component of a particular model.

Locate the first break in the repeat

If the closed section appears broken, inspect origins, size and spacing tooth by tooth from below the slider to find the first error instead of squeezing the whole row through scaling. Check attachment for floating upper teeth. For corners protruding beneath the slider, inspect stacking and coverage range instead of concealing them with a large shadow. Restore diagnostic side colours by the naming list. After repairs, inspect both uncovered structure and complete image. Repetition, open/closed regions and local occlusion should support observation rather than merely accumulate similar rectangles.