The Wrong Question
Brands looking at glass packaging decoration often ask "which is more durable — hot stamp or silk print?" This is the wrong framing. In practice, a well-applied silk print lasts just as long as a well-applied hot stamp. A poorly applied version of either will fail within months.
What determines durability is not the process — it is the materials used, the application parameters, and whether the factory tests the result against the actual conditions the bottle will face in use.
The Two Types of Decoration — Logo vs Bottle Surface
Before comparing processes, it helps to understand there are two separate decoration decisions for any bottle:
- Logo processes — applied to add your brand identity to the bottle surface: silk printing and hot stamping.
- Bottle surface processes — applied to change the visual character of the entire bottle: electroplating, colour spraying, and frosting.
Most bottles use one logo process plus one or more surface processes. A frosted bottle with a hot-stamp gold logo uses two processes. An ombre-sprayed bottle with silk-printed Arabic calligraphy uses two processes. Understanding this separation helps when briefing a factory on what you want.
Logo Processes — Silk Printing and Hot Stamping
Silk Printing
Ink forced through a mesh screen, kiln-cured at high temperature. Allows logos, calligraphy, patterns, full colour artwork.
Best for: complex logos, Arabic script, multi-colour artwork, gradient effects.
Cost: +$0.08–$0.15 per unit per colour
Hot Stamping
A heated die presses metallic foil onto the glass. Creates a crisp, permanent metallic logo — gold, silver, rose-gold, holographic.
Best for: single-colour metallic logos, brand names, fine-line graphics.
Cost: +$0.10–$0.18 per unit
Bottle Surface Processes
Electroplating
Metal coating deposited via electrochemical process. Creates a mirror-like metallic surface. Chrome, gold, copper tones available.
Best for: full metallic bottle effect, luxury cap decoration.
Cost: +$0.25–$0.60 per unit
Colour Spraying
Mineral paint sprayed and kiln-cured. Creates solid or ombre (gradient) bottle colour. Pantone-matched.
Best for: brand colour identity, ombre/gradient effects.
Cost: +$0.10–$0.20 per unit
Frosting
Chemical etch or sandblast creates a matte, diffused surface. Permanent — the finish is part of the glass.
Best for: premium tactile feel, skincare and serum brands.
Cost: +$0.08–$0.18 per unit
Combined Finishes
Two or more processes on one bottle — e.g. frosted body + hot-stamp gold logo. Creates the most differentiated result.
Best for: premium positioning where the bottle is part of the brand experience.
Cost: cumulative — add individual process costs
The Three Tests — Our Factory Standard
At Loci Glass, every decoration — regardless of which process — must pass three tests on production samples before any bulk order is approved for shipment.
75% Alcohol Rub Test — 200+ Cycles
A cloth saturated with 75% isopropyl alcohol is rubbed across the decorated surface 200 times under standardised pressure. Pass condition: zero visible fade, lift, transfer, or colour change. This test simulates the alcohol contact that happens routinely in a beauty routine environment — and it catches budget-tier inks that look fine in a sample but fail after weeks on a vanity.
Cross-Hatch Adhesion Test (九宫格) — ISO 2409
A grid of 25 squares is cut through the decoration layer using a cross-hatch cutter. Tape is applied firmly over the grid and pulled sharply. Pass condition: zero squares detach from the glass surface. This tests the adhesion between the decoration material and the glass substrate — the primary failure mode for spray coatings and silk prints that were not correctly cured.
Perfume Compatibility Test — 24–48 Hours Direct Contact
The decorated surface is exposed to the actual perfume formula (not just alcohol) for 24–48 hours. Pass condition: no colour change, no surface softening, no visible attack. This test matters because fragrance compounds — particularly musks, aldehydes, and natural extracts — are complex chemical environments that can attack certain ink chemistries that would pass an alcohol test alone.
- "Do you test your decoration with actual perfume formula, or only with alcohol?" — The answer tells you their real quality standard.
- "What is the standard for your cross-hatch adhesion test — how many squares can fail?" — Pass condition should be zero.
- "How many alcohol rub cycles do you test to?" — 200+ is the professional standard.
- If a supplier cannot answer these questions specifically, their quality standard is likely informal.
Want to see our test results on a sample?
We provide decoration test certificates with every sample order. Request a sample and we will include the test documentation.
Request a Sample