Compliance
STC vs Rw: Why Your 45 dB Window Gets Graded at 39
STC vs Rw sound ratings differ by 1-2 points, but Rw+Ctr can cut 6 dB. What each index measures, which market grades on which, and how to write the acoustic line.
Field Notes
Tips and guides for adding size annotations to your product images
Size & Fit
Full Overlay vs Half Overlay: Two Answers, 9.5 mm Apart
Full overlay vs half overlay means different geometry on face-frame and frameless cabinets: the door-size math, the reveal, and what to ask before cutting.
B2B & Suppliers
Shore A vs Shore D: Why 'Shore 70' Is Not a Spec
Shore A vs Shore D hardness are two instruments, not two precisions: why 'Shore 70' is not a spec, why no conversion exists, and how to write a callout that holds.
Compliance
Stair Riser and Tread Dimensions: The 3/8-Inch Rule
Stair riser and tread dimensions are capped by two numbers per market, and failed by a third: no riser may differ from another by more than 3/8 inch. Limits for four markets.
B2B & Suppliers
Ra vs Rz: Same Number, Two Completely Different Surfaces
Ra vs Rz measure different things — two parts can share an Ra and only one will seal. What each parameter sees, why no conversion factor works, and what ISO 21920 changed.
Size & Fit
What Size Dining Table Seats 8? Run the Clearance Math
What size dining table seats 8 takes three numbers, not one: edge length per person, table width, and the clearance behind the chairs. With the full sizing table.
B2B & Suppliers
Cover Width vs Overall Width: 1,000 mm That Covers 840
Cover width vs overall width decides panel count: a 1,000 mm sheet covers 840 mm. The profile table, the panel-count formula and where the 25% shortfall comes from.
Size & Fit
How to Measure VESA Mount Size: 3 Numbers, Not 1
How to measure VESA mount size: horizontal spacing, vertical spacing and thread. The full MIS-B to MIS-F table, plus the screw length that cracks panels.
Compliance
IP68 vs IP66: Why the Higher Number Can Fail a Hose Test
IP68 vs IP66 is not a ranking: in IEC 60529 the water tests stop being cumulative after 6. What each digit certifies, and what belongs on your spec sheet.
Seller Growth
Made-to-Measure Orders: Lock These 6 Things Before Quoting
The made-to-measure order process: who owns a wrong dimension, opening vs product size, the change freeze point, and when custom goods lose the 14-day return right.
Size & Fit
Tolerance Stack-Up Explained: 5 Good Parts, 1 Bad Fit
Tolerance stack-up explained: 5 parts at ±0.5 mm give ±2.5 mm worst case but ±1.118 mm RSS. When each method is right, and why ISO 2768-mK is now half obsolete.
Photography
How to Photograph a Product for Measurement: 4 Setups
How to photograph a product for measurement: lens distortion and perspective error are different problems. At 1 m, 100 mm of depth costs 11% in size. Four setups ranked.