Material Hub · Optics
Crystal & Optical Glass
Refractive index, dispersion, K9 borosilicate versus full-lead crystal, and California Prop 65 surface-lead rules.
AI vs. the lighting workshop
Ben Yang films lighting craftspeople in Guzhen, China, and tests what AI models say about lighting against physical workshop measurements.
01 / Physical verification
Measured on the bench, not guessed in a chat window
I am not a thirty-year lighting veteran. I started driving across the Pearl River from Shenzhen to Guzhen three or four days a week to build one crystal table lamp without getting fooled. Whenever a frontier AI model and a workshop craftsperson give opposite answers, we put the specimen on an instrument — refractometer, integrating sphere, handheld XRF analyzer, or thermal probe — and publish the raw reading.
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- AI was right
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- The master was right
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- Both were wrong
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- Unresolved
Episode 1 is currently in post-production. We never log unfilmed or simulated verdicts on the scoreboard. Read our testing methodology and evidence grades while we prepare the first batch of measured optical and electrical rows.
02 / Materials & engineering
Material studies & decision guides
Material Hub · Metallurgy
Solid Brass vs. Plated Alloys
How Guzhen machine shops turn H62 and H65 brass, why electroplated steel pits near coastal air, and lacquer trade-offs.
Decision Guide · Electrical
24V Low-Voltage Table Lamps
Why separating mains AC into an external UL Class 2 adapter lowers lamp-body heat, simplifies service, and avoids false UL claims.
Complete reference index
K9 Optical Crystal vs. Lead Crystal in Lighting
Lead crystal disperses wider spectral fire than K9 optical glass, while K9 weighs less, resists scratching and adds no lead oxide.
Lead Oxide in Crystal Lamps and California Prop 65
Leaded crystal glass contains bound lead oxide and requires a California Prop 65 lead warning; K9 optical glass has no lead added.
How to Clean Faceted Crystal Without Clouding or Scratching
Unplug the lamp, dust dry first, and wipe facets with distilled water and isopropyl alcohol on lint-free microfiber — never ammonia.
US Lighting Compliance Guide
What UL 1598, UL 153, external Class 2 24V adapters, DOE Level VI, FCC Part 15B, Prop 65, and US DDP entries actually require.
03 / Bespoke engineering
Custom projects, led by Amy
Need a custom chandelier, architectural brass sconce run, or hospitality luminaire built across Guzhen’s specialist workshops? My partner Amy leads custom projects through a transparent three-stage process:
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01
Free project brief — Send dimensions, site photos, or a PDF moodboard. Amy replies with a realistic workshop budget range within 2 business days.
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02
Design development deposit — Crystal and brass finish samples, US/EU electrical compliance pathway selection, and structural weight review.
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03
50% production deposit — Full CAD shop drawings (DWG) for sign-off, Guzhen fabrication, and pre-shipment optical & thermal testing.