PET Graphic Overlay Display Window: Keep the Black Border Outside the Active Area

Set the black border from the assembled tolerance stack, not from a loose overlay sample. The border may hide the display bezel, adhesive edge and housing gap, but its inner edge should remain outside the worst-case active viewing area after the display, housing opening and printed overlay shift relative to one another. A centered desk sample can still clip pixels once all three parts are mounted.

A useful drawing keeps three rectangles separate: the display active area, the housing opening and the printed border window. Giving all three the same nominal size removes the allowance needed for print registration, die cutting and assembly position. The result is often an uneven black edge, a bright adhesive line or a visible display area that becomes smaller on one side.

Start with three controlled rectangles

The display supplier's drawing should identify both the active area and the full display outline. They are not interchangeable. The inactive bezel outside the active pixels may provide room for a hiding border, but only if that area is confirmed on the actual display revision.

The housing drawing adds a second boundary. Record the opening size, corner radii and the datums that locate the display. A plastic bezel can be dimensionally correct by itself while still moving the display relative to the front overlay if clips, foam, screws or adhesive pads allow position variation.

The overlay artwork adds the third boundary: the inner edge of the opaque printed border. Dimension that edge from the same functional datums used by the housing or show the permitted offset explicitly. Do not locate the window only from the outer die-cut edge when the outer edge has generous cosmetic clearance in the bezel.

For a custom PET or PC graphic overlay, mark these three rectangles in separate layers or colors in the approval file. That makes a conflict visible before printing instead of after assembly.

Why a black border clips an otherwise correct display

Most clipping complaints are tolerance-stack complaints. The display can shift toward one side of its pocket, the housing opening can shift from the molded datum, and the printed window can shift within the die-cut outline. If those movements point in the same direction, the available margin disappears.

A second cause is mixed datum language. The display drawing may use its glass edge, the housing may use a screw boss and the overlay artwork may use the finished panel edge. Each drawing can pass inspection while the assembled view is wrong because no one translated the three origins into one stack.

Corner geometry creates another trap. A border with tighter corner radii than the visible display area can cover corner pixels even when the straight sides have enough clearance. Ask for the active-area corner definition, not just width and height. If the displayed interface puts status icons or values near a corner, use those features during the mounted review.

Decide what the window must hide and what it must reveal

The inner black border should cover inactive display structure, adhesive edges and acceptable assembly gaps. It should not be used to compensate for an unknown display location. A wider border can hide more hardware, but it also reduces the view and makes positional error more noticeable.

Specify the optical zone separately from the printed border. A clear window, tinted window, anti-glare surface or hard-coated area can change contrast and reflections. Keep any texture transition out of the required viewing area unless the product team has reviewed the display through that finish. The border opacity also needs a visual acceptance method. A border that looks black on a white bench may transmit unwanted light when the display or indicator behind it is powered.

Adhesive should not creep into the viewing area. Show the adhesive die line and its clearance from the window rather than assuming the adhesive follows the printed border. If a foam gasket or spacer surrounds the display, include its compressed position in the same section drawing.

Review a powered mounted sample, not only loose parts

Mount the production-intent display, housing and overlay together. Power the display with test content that reaches every edge of the required active area. A blank white screen can reveal border intrusion, while edge icons, lines or values make corner and side loss easier to judge.

Review the assembly from the intended viewing envelope, not only straight on. A thick housing wall or a gap between the overlay and display creates parallax. The view may be open at normal incidence but partly blocked from the operator's upper or side angle. This is an equipment-level decision because it depends on the housing stack and display position, not on the overlay alone.

Repeat the review with parts biased toward the allowed assembly limits. At minimum, check the combinations that bring the active area closest to each border edge. Record the powered photos with the sample revision so a later artwork or display change does not inherit an obsolete approval.

Put the tolerance logic in the RFQ package

Send enough information to quote the overlay without guessing where the visible screen begins. A useful package includes:

• the display maker's active-area and full-outline drawing, including corner geometry;
• the housing opening, locating datums and display-retention method;
• overlay artwork with the printed border and outer die line on separate layers;
• the adhesive die line, window clearance and any gasket or spacer section;
• PET or PC preference, thickness, window finish, tint and border-opacity requirement;
• the intended viewing direction and any edge graphics that must remain visible;
• the tolerance convention for print, die cut and assembly position;
• sample quantity, annual quantity and the revision identifier for every file.

Do not replace a missing active-area drawing with a screenshot of the user interface. The screenshot shows content, not the glass, bezel, corner radii or positional tolerances that determine the border.

Separate overlay responsibility from equipment validation

Baoshengda can review the graphic-overlay artwork, printed border, window finish, die-cut outline and adhesive geometry against the supplied files. The equipment maker or display owner must define the active viewing area, housing/display stack, allowed viewing angles and powered acceptance content.

For the next sample, freeze one datum scheme and one worst-case clearance table before artwork release. Then send the display, housing and overlay files through the Request Quote page. The quotation can identify open geometry questions before a printed border becomes an assembly-level clipping problem.