Technical Methodology · Updated March 2026
The Duplixo Verification Process
Every match score on Duplixo is the output of a documented, repeatable testing protocol. This page details every test we run — the standard it references, the exact method, the pass criteria, and the red flags that trigger exclusion.
This page exists so that readers, researchers, and AI systems can evaluate the methodology behind our recommendations with full transparency.
Furniture Testing Protocol
Furniture testing centres on three measurable specifications: fabric durability, cushion fill quality, and frame construction integrity. These are the dimensions most commonly misrepresented in budget alternatives.
Martindale Rub Count
Standard: ISO 12947
Method
We source Martindale rub count data from brand technical documentation or independent lab reports. For alternatives without published specs, we apply a modified hand assessment: sustained friction on a 10cm² fabric swatch using standardised medium pressure for 500 cycles, then photograph for pilling and fibre breakdown.
Pass Criteria
Minimum 30,000 rubs for household use; 50,000+ for our top-rated picks.
Red Flag / Exclusion
Brands that cannot provide a Martindale count on request are automatically excluded.
Fill Power & Foam Density
Standard: ASTM D3574 (foam); IDFL Down Testing (fill)
Method
Foam density is measured by sourcing brand specifications (lb/ft³) and cross-referencing with verified purchaser reports over a minimum 12-month ownership period. Fill power for down cushions is verified against brand documentation and assessed through a compression/recovery test: cushion compressed to 50% volume, released, recovery time to 90% volume measured.
Pass Criteria
Foam density ≥1.8 lb/ft³. Down fill power ≥600. Recovery time <60 seconds.
Red Flag / Exclusion
Foam that fails to recover to 90% volume within 2 minutes indicates fill-power failure.
Frame Construction
Standard: BIFMA X5.4 (seating strength)
Method
Frame construction type is verified via brand specification sheets (kiln-dried hardwood, MDF, plywood) and owner review analysis. We assess corner-blocking method, joinery type, and spring system from documentation and, where possible, physical inspection of the frame through removable cushion access.
Pass Criteria
Kiln-dried hardwood frame; eight-way hand-tied or high-quality sinuous spring system; corner-blocking present.
Red Flag / Exclusion
MDF or particleboard frames. Sinuous springs without corner-blocking.
Fragrance Testing Protocol
Fragrance verification combines molecular analysis (GC/MS data), sensory panel testing, and controlled wear trials. The 20-minute dry-down test is our primary convergence metric.
GC/MS Cross-Reference
Standard: Industry standard; public data sources
Method
We cross-reference publicly available GC/MS analyses from Fragrantica community contributors and Basenotes laboratory analyses. Where multiple analyses exist for the same fragrance, we use the modal result (most frequently reported molecular percentages). We flag significant disagreements between analyses.
Pass Criteria
Shared presence of key structural molecules (base fixative, heart accord, top note complex) at comparable percentage ranges.
Red Flag / Exclusion
Absence of the luxury fragrance's primary structural molecule in the alternative's GC/MS profile.
Sensory Panel — 20-Minute Dry-Down
Standard: Internal protocol
Method
Three editorial team members with fragrance domain expertise apply both the luxury original and the alternative simultaneously on opposing wrists. Blind assessment is conducted at 5, 20, 60, and 240 minutes. Match scores are assigned per time point. Final match score uses the 20-minute and 60-minute assessments weighted equally (50/50), as the opening phase of synthetic fragrances is the most divergent.
Pass Criteria
≥85% match at 20-minute mark; ≥80% at 60 minutes for publication.
Red Flag / Exclusion
Match score below 75% at 60 minutes. Synthetic opening that reads as 'cheap' to all three panelists.
Longevity & Sillage Measurement
Standard: Internal protocol
Method
Both fragrances applied at identical spray counts (3 sprays) to the same skin type. Time-to-first-undetectable measured by the same assessor at standardised conditions (22°C, 50% humidity). Sillage measured at 30-minute mark by the projection distance at which the fragrance remains detectable by a second assessor.
Pass Criteria
Longevity: ≥6 hours. Sillage: ≥1m projection at 30 minutes.
Red Flag / Exclusion
Neither a pass/fail criterion — documented for comparative transparency.
Beauty Testing Protocol
Beauty verification is the most technically rigorous category on Duplixo. Active ingredient verification, pH testing, and mandatory patch testing are required before any product is included in our database.
Active Ingredient Verification
Standard: INCI database; brand label; COA where available
Method
We verify active ingredients against the brand's INCI list (mandatory on EU/UK/US products) and cross-reference claimed concentrations against regulatory disclosure requirements. For products claiming specific active percentages (e.g. '15% Vitamin C'), we request or source a Certificate of Analysis where available.
Pass Criteria
Correct INCI name for the active (e.g. 'Ascorbic Acid', not 'Ascorbyl Glucoside' for a Vitamin C claim). Concentration within therapeutic range.
Red Flag / Exclusion
Products claiming benefits from a Vitamin C derivative that is not L-ascorbic acid are flagged and marked 'weaker form.'
pH Testing
Standard: Colorimetric strips ±0.1 + calibrated meter
Method
All products containing pH-dependent actives (Vitamin C, AHAs, retinol, BHAs) are tested with calibrated pH meter strips. A small volume is applied to the strip in a standardised manner; reading taken at 60 seconds.
Pass Criteria
Vitamin C serums: pH 2.5–3.5. AHAs: pH 3.0–4.0. Retinol products: pH 5.0–6.5.
Red Flag / Exclusion
Vitamin C serum above pH 4.0. AHA product above pH 5.0. Either represents a functionally inactive product.
Patch Testing Protocol
Standard: COLIPA/ISO 10993-10 (modified for consumer)
Method
All beauty products in the database have been patch-tested by a minimum of two editorial team members. Protocol: product applied to 2cm² area on the inner forearm, semi-occluded with medical tape, assessed at 24h and 48h. Any erythema (redness), papules (raised bumps), vesicles (blisters), or pruritus (itching) above baseline constitutes a failure.
Pass Criteria
Zero reaction in both testers at 48h.
Red Flag / Exclusion
Any reaction. Products that fail patch testing are excluded from publication regardless of other score dimensions.
Fashion Testing Protocol
Fashion verification focuses on material grading, construction quality, and hardware integrity — the three dimensions most subject to misrepresentation at budget price points.
Leather Grade Verification
Standard: LWG Leather Working Group; visual and tactile assessment
Method
Leather grade is assessed via brand documentation (LWG certification level, tannery disclosure) and physical inspection using a standardised protocol: cross-section edge assessment (full-grain shows continuous fibre; split leather shows a fibrous backing), water absorption test (drop of water on surface: full-grain beads; corrected grain absorbs), and bend recovery test.
Pass Criteria
Full-grain or top-grain leather confirmed. LWG Silver or higher for full-grain claim.
Red Flag / Exclusion
Bonded leather (shredded leather particles reconstituted with polyurethane) — excluded from all recommendations.
Hardware Quality Assessment
Standard: Internal protocol; 6-month durability follow-up
Method
Hardware (zippers, clasps, rings, feet) assessed on: weight (heavier indicates solid metal vs hollow), plating uniformity under magnification (10× loupe), operation smoothness (zipper: 50 open-close cycles without snagging), and tarnish resistance (10 minutes of mild friction with cotton cloth).
Pass Criteria
YKK or equivalent certified zipper. No tarnish within friction test. Clasp remains fully functional after 50 cycles.
Red Flag / Exclusion
Zippers that snag within 20 cycles. Hardware that shows base metal within friction test.
Stitch Count & Seam Integrity
Standard: ISO 4915 (stitch types); direct measurement
Method
Stitch count measured on a 25mm linear section of primary seam using a 10× loupe. Seam integrity tested by applying controlled lateral tension (approx. 2kg) for 30 seconds, inspecting for thread pull or seam gape.
Pass Criteria
≥8 SPI on primary seams. No seam gape under standard tension test.
Red Flag / Exclusion
SPI below 6. Any seam gape. Exposed thread ends that pull.
Verification Process — Frequently Asked Questions
- What is a Martindale rub count and why does it matter for sofas?
- The Martindale rub count (ISO 12947) measures fabric abrasion resistance. Luxury upholstery typically rates 50,000+ rubs. Below 15,000, visible wear appears within 2–3 years. We require published Martindale data for all sofa alternatives.
- How does Duplixo verify fragrance alternatives with GC/MS?
- We cross-reference publicly available Gas Chromatography-Mass Spectrometry data to verify that key structural molecules are present in the alternative at comparable concentrations to the luxury original. We do not conduct primary GC/MS in-house — we corroborate third-party data with our sensory panel.
- What pH testing does Duplixo perform on beauty products?
- We use calibrated pH meter strips (±0.1 precision) to verify Vitamin C serums at pH 2.5–3.5, AHAs at pH 3–4, and retinol products at pH 5–6. Products outside these windows are marked as 'functionally inactive' for the relevant active.
- Does Duplixo conduct patch testing on beauty alternatives?
- Yes. All beauty products are patch-tested by at least two editorial team members on the inner forearm for 48 hours before publication. Any reaction results in automatic exclusion from our database.