Overview
VSHighViz Calculator evaluates high-visibility (hi-vis) workwear garments against two standards it actively calculates against: ANSI/ISEA 107-2020 (USA/North America) and EN ISO 20471:2013+A1:2016 (Europe/international). Both standards define minimum areas of fluorescent background material and retroreflective tape that a compliant garment must carry. The plugin measures these areas directly from VStitcher pattern pieces — not from a photo or a spec sheet — and evaluates them against the thresholds below.
Pattern pieces are auto-classified by location (front, back, sleeve, waistband, hood) from their names, producing a front/back split against ANSI's balance-of-design rule. A location group only appears if the garment actually has pieces classified into it — a trouser never shows a sleeve/hood row, a jacket never shows a waistband row.
Requirements
VStitcher 2025.3.0 or newer, bw-api 3.x
No data leaves the local machine — no network calls are made
Material Tagging
Before calculating, every material in the garment must be tagged (untagged materials are ignored):
Plugin tag | What it is | Role in compliance |
| Retroreflective tape (strips, bands) — requires a declared width in mm | Counts toward the retroreflective (RR) area total |
| Retroreflective woven fabric | Counts toward the retroreflective (RR) area total |
| Fluorescent background fabric (yellow, orange, red) | Counts toward the fluorescent background (BG) area total |
Areas covered by prints, overlaid panels, or other garment elements are excluded from compliance calculations under both standards — the plugin's per-shape scan only counts material that is actually assigned to boundary edges, internal lines, or design lines, not incidental overlaps.
How to Calculate Coverage
Step 1: Tag Materials
Open a garment, click Plugins → Calculate Hi-Viz Coverage, and tag each material as Reflective Tape, Reflective Fabric, or Hi-Viz Base (tape materials also need a declared width in mm).
Step 2: Calculate and Review
Click Calculate Coverage, then review area, compliance, and front/back split results per size.
Step 3: Export
Export results as PDF or JSON.
Piece Location Classification & Front/Back Split
Each pattern piece is classified by keyword-matching its shape name into one of: front, back, sleeve, hood, waistband, or other. Sleeve/hood/waistband keywords are matched first (e.g. sleeve, hood/balaclava, waistband/yoke/fly); anything left unmatched falls to front/back/other. A location group is only shown in the results if the current garment actually has at least one piece classified into it.
Once every piece's tape area is attributed to its shape, front/back totals are built as follows:
Location | How it counts toward the front/back tally |
Front, Back | Counted directly toward that side |
Sleeve, Waistband, Other | Split 50/50 into both the front and back tally |
Hood | Excluded entirely — consistent with the hood-down assessment position (a lowered hood covers whatever tape sits beneath it on the back) |
The resulting front_pct / back_pct are checked against ANSI's 40% balance-of-design floor (below) to produce a pass/fail per side, alongside the combined-total pass/fail.
ANSI/ISEA 107-2020
Enforced indirectly — OSHA's General Duty Clause plus 29 CFR 1926.651(d)/1926.201; 23 CFR Part 634 (FHWA) is the one direct mandate, and only for federal-aid highway workers exposed to traffic. Certification is self-declared: materials must be lab-tested by an ISO/IEC 17025-accredited lab, but the finished garment itself requires no third-party evaluation — only a manufacturer Declaration of Conformity.
Type and Class
Type | Intended use |
O (Off-road) | Non-roadway environments — warehouses, parking lots |
R (Roadway) | Highway/roadway work zones |
P (Public Safety) | Law enforcement, fire, EMS |
Minimum Area Requirements
Type | Class | Fluorescent Background | Retroreflective |
O | 1 | 217 in² (~1,400 cm²) | 155 in² (~1,000 cm²) |
O | 2 | 775 in² (~5,000 cm²) | 201 in² (~1,297 cm²) |
R | 2 | 775 in² (~5,000 cm²) | 201 in² (~1,297 cm²) |
R | 3 | 1,240 in² (~8,000 cm²) | 310 in² (~2,000 cm²) |
P | 2 | 775 in² (~5,000 cm²) | 201 in² (~1,297 cm²) |
P | 3 | 1,240 in² (~8,000 cm²) | 310 in² (~2,000 cm²) |
Small-size exception: for the smallest offered size (XS/S) in a product line, the fluorescent background minimum reduces to 540 in² for Type R/P Class 2. The retroreflective minimum is unchanged.
Balance-of-Design Rule
Each of front and back must independently carry at least 40% of the required minimum retroreflective area — the only per-side constraint in the standard; the top-level minimums otherwise remain combined totals. Example for Type R Class 2 (201 in² total): front must show ≥ 80.4 in², back must show ≥ 80.4 in². This is exactly what the plugin's front/back split (above) evaluates.
Shoulder-Area Requirement
When sleeves do not have retroreflective tape fully encircling them, the standard requires 150 cm² (23.25 in²) of retroreflective material in the shoulder area (front + back combined) to maintain 180-degree visibility. This is a placement/configuration rule, not a standalone area minimum, and is not separately evaluated by the plugin today.
EN ISO 20471:2013+A1:2016
Mandatory under the EU PPE Regulation (2016/425) — hi-vis apparel falls under PPE Category II or III, both requiring third-party Notified Body conformity assessment before CE marking. This is the core structural difference from the US model: the EU requires third-party sign-off on the finished garment itself; the US self-declares it.
Class System
Class | Risk level | Typical garments |
1 | Low | Vests, waistcoats in low-speed environments |
2 | Medium | Jackets, trousers — most common commercial hi-vis |
3 | High | Full-coverage garments — motorway, rail, emergency services |
Minimum Area Requirements
Class | Fluorescent Background (m²) | Retroreflective (m²) |
1 | 0.14 | 0.10 |
2 | 0.50 | 0.13 |
3 | 0.80 | 0.20 |
These are aggregate garment-level totals — the standard does not subdivide into separate front/back floors (unlike ANSI's balance-of-design rule above).
Tape Width Rule
EN ISO 20471 requires retroreflective tape to be at least 50 mm wide to count toward retroreflective area. The plugin applies this automatically: when evaluating EN ISO compliance, any reflective_tape material with a declared width below 50 mm is excluded from the EN ISO retroreflective total (though it still counts toward the separate ANSI total, which has no such width floor), and a warning is shown in the compliance panel.
Measurement Protocol
Areas are measured on the smallest finished size of a product range, not an average or largest size.
Covered areas (branding, overlaid panels) are excluded.
Compliance is assessed in a fixed garment configuration — wearer adjustments that reduce visible area (tucking bands into boots, layering) break compliance.
The A1:2016 amendment added breathability testing; it did not change the Table 1 area minimums above.