DSS-Co.02.01 — Roller Pickup / Line Ghosting (Pyrolytic Line)

Roller pickup/line ghosting (pyrolytic line) is an appearance change confined to pyrolytic (hard-coat) low-E or comparable high-temperature functional coatings. It presents as quasi-parallel, longitudinal bands (machine/transport direction) at spacings consistent with support/transport rollers, with subtle sheen or color shift (ghosting). The phenomenon is planar within the coating and usually non-tactile. Classification is appearance-only per VIS (method-agnostic). Inspect after Non-Invasive Reveal under VIS lighting/geometry; record surface numbering and worked-surface status.

Face identification is critical. Pyrolytic hard-coats are commonly placed at #2 in IGUs (or #1/#4 where design requires). Confirm coated face before classification.

• Multiple, parallel, low-contrast bands running consistently in one direction (line direction); band width and pitch repeat pane-to-pane within a lot.
• Bands read as sheen shift / slight color cast in reflection; contrast rises under oblique sweep and raking.
• May co-present with very faint roller “kiss” arcs at edges or entry/exit zones.

Surface-catch class (MSRT)

• SC-0 (planar optical variation within coating; no surface relief).
• SC-1 rare, where lightly textured pickup or fine particulate imprint provides very shallow relief.
• Perform one light, non-marring pass on a small revealed test patch. Use a polymer stylus only on suspected coated faces. MSRT supports classification only; do not abrade the coating.

Visual signature

• Quasi-parallel stripe set; fixed pitch and consistent direction across the pane; no chip-flank sparkle, no discrete pits.
• Planar behavior: bands persist uniformly when moving viewpoint along the band; no localized “worked region” edge.
• Often lot-repetitive: adjacent lites from same supply may show identical spacing/orientation.

Viewing / lighting

• Evaluate clean & dry at 12 / 36 / 72 in, normal and oblique sweep (~60°-120°); raking amplifies sheen shift; use broad specular reflection to read band pitch. Record distances/angles in-frame.

Location / access

• Record pane ID and surface numbering (#1-#4; laminate-internal). If the anomaly is on #2/#3 within an IGU, it is inaccessible in place → CAT-5 by location for in-place restoration scope (classification remains Co.02.01).

Mechanism cue (context)

• Pyrolytic deposition or hot handling history; consistent line direction with roller transport; lot repetition; absence of field activities that cause scoring or chemical halos.

Assign CAT by visibility at acceptance geometry and MSRT. Depth values are indicative-field measurement not required.

• CAT-1 (Benign / non-relief): Faint banding legible mainly at oblique/raking; SC-0; minimal impact at standard view. Indicative relief: 0-10 μm (film-level optical only).
• CAT-2 (Light): Discernible bands at standard distance in certain lighting; SC-0 (or rare SC-1 if lightly textured pickup). Indicative relief: ~10-40 μm (apparent optical).
• CAT-3 (Moderate): Pane-noticeable band set at standard distance across significant area; SC-0/SC-1; clearly affects uniform appearance. Indicative relief: ~40-120 μm (apparent optical).
• Reclassify when: If chip-flank sparkle or tactile grooves appear → M.01 Linear scoring; if uniform granular frost in masked regions → V.01.01 abrasive blast; if runs/cream swirls exist → V.02 chemical etch; if peppered fused nodules present → Th.01.02 hot particle.
• CAT-5 (by condition/location): Anomaly on #2/#3 (between panes) or coating-side to be worked where compliant presentation cannot be achieved → CAT-5.

CAT is appearance-based; acceptance is separate under VIS-A at 12/36/72 in. Do not abrade coated faces to “force” a response.

• vs. M.01/M.02 mechanical: Mechanical defects show directional grooves/swirl with SC-1/SC-2 and chip-flank sparkle; Co.02.01 is planar sheen shift, typically SC-0.
• vs. Co.01 sputtered low-E patchiness: Sputtered films often show color non-uniformity without roller-pitch periodicity; pyrolytic roller ghosting shows regular spacing aligned to transport direction.
• vs. Ch.03 mineral staining/etch: Mineral systems show ringed halos/runs and can be SC-1/SC-2; roller ghosting lacks wetting geometry and remains lot-repetitive.
• vs. E.01 atmospheric film: Atmospheric films are random or flow-mapped and lift on reveal; roller ghosting persists and is coating-intrinsic.

• Photo set (VIS): 12 / 36 / 72 in, normal + oblique; raking macros across band transitions; overview frames capturing parallelism and pitch. Record distance/angle in-frame.
• Face ID + MSRT. Confirm coated surface via project documentation or controlled reflection tests; MSRT (polymer stylus only) on a small reveal patch: record SC-class (SC-0 typical).
• Lot/replication check. Where possible, document adjacent lites for repeated spacing/orientation (supports coating-intrinsic attribution).
• Forms: Pane ID; product family & surface numbering; worked surface Y/N; functional coating present on worked surface? (Y/N/Unknown); reveal status; lighting/time; geometry checklist; photos attached.
• Acceptance split: Post-restoration acceptance per VIS-A §6; classification ≠ acceptance. Coated-face appearance rules apply per VIS §6.2.e when the worked surface is the functional coating.

• Co.02.01 Roller Pickup / Line Ghosting (Pyrolytic) - Quasi-parallel sheen-shift bands at consistent roller pitch on surface #___ (pyrolytic hard-coat confirmed); MSRT (polymer): SC-0 [SC-1 localized if applicable]; visible at [12/36/72 in] under VIS geometry. Morphology: planar coating variation, no chip-flank sparkle, no pits/runs. Classification: CAT-[1/2/3] by visibility; reclassify per notes if mechanical/chemical indicators present; CAT-5 if between-pane or coating-side constraints preclude in-place work. Forms + photo set attached; acceptance per VIS-A §6.