Author: Steve Jewell, Flippee.com
Time to read: 8 minutes
Time to skim/look at pictures: 2 minutes
The Science of UV Protection for your Cards – Showcase Without Sacrificing Their Grade
Should you Vault Your Cards or Display Them?
What to do??? You place the card of your lifetime with shaking hands into a brand new magnetic protector. Then, reality hits you: What on earth do you do with it now? The most cautious collectors place it in bubble wrap and store it in their safe – NEVER let light touch its surface. But what is the point of owning this masterpiece if nobody—not your friends, and not even you—can ever look at it? Cards were designed to be celebrated, admired, and shared. But the moment you bring that gem out, an invisible, silent predator is waiting to attack: Ultraviolet (UV) radiation. This article discusses how to provide the best UV protection for cards – including your HOF Rookie card!
Do we Store Safely or View Carefully?
Can Sunlight Ruin My Card?
The short answer is absolutely yes.
To understand how to protect your cards, we first have to understand light. The light from the sun or your lamps feels gentle, warm, and harmless (see Figure 1). But light travels in tiny energy packets called photons, which move in waves of varying lengths measured in nanometers (nm).
Human eyes can only see a small portion of the electromagnetic spectrum—roughly between 400 nanometers (violet) and 700 nanometers (red). Just beyond the violet edge of visible light lies Ultraviolet (UV) radiation, ranging from 100 to 400 nm. Because UV wavelengths are shorter than visible light, their individual photons carry way more energy (measured in electron volts, or eV).
Key Takeaways:
Best Display Material for Trading Card
Standard Glass: Blocks only ~25% of UV-A radiation; poses high shatter risk to cards.
Standard Acrylic (Plexiglass): Impact-resistant, but filters only 40%–50% of cumulative UV light.
Optical Polycarbonate: The gold standard for display security, blocking up to 99.5% of harmful UV rays while offering 250x the impact resistance of glass.
Optimal Environment: Keep cards out of direct southern/western sun, switch to LED lighting, and maintain 45% relative humidity.
Figure 1 – The Light Spectrum and How Light Affects your Card
When high-energy UV strikes a trading card, it triggers three destructive chemical phenomena:
- Photolysis – Photons with high energy break down the chemical bonds of organic dye molecules (the inks that make up player jerseys, logos, and borders), causing fading or color change.
- Photo-Oxidation: UV photons create free radicals that oxidize printed inks, causing bleaching and turning your cards into dull, chalky ghosts.
- Substrate Breakdown (Cellulose Yellowing): Cardstock is made from natural cellulose wood fibers. Ultraviolet energy breaks those cellulose chains, turning crisp white borders sickly yellow and rendering vintage cardboard brittle enough to crack.
GRADING ALERT: A single year of sunlight exposure through an untreated glass window can strip 60% of a card’s magenta and yellow ink density. Once gone, no restoration, grading press, or conservationist can bring those colors back. |
The Great Material Face-off:
Visibility vs. Durability vs. Attenuation
The display industry relies on three primary clear materials: glass, acrylic (Plexiglass), and polycarbonate. Each brings distinct physical properties to the table.
When evaluating materials for trading card displays, there are three essential measures:
- Optical Visibility: How much visible light passes through (transmittance) versus how much reflects or distorts the card’s surface details (refractive index and optical haze).
- Mechanical Durability: What happens when the display is knocked off a table, bumped by a curious pet, or dropped during a trade night? Does it bounce, crack, or shatter into microscopic razor shards?
- UV Attenuation: How effectively does the material attenuate (block) photon transmission across the 280–400 nm UV spectrum?
Display Materials
Standard Glass: Standard window glass is used in 95% of inexpensive retail picture frames. While it is flat and scratch resistant, it’s a disaster for card preservation. Standard glass allows up to 75% of high-penetration UV-A radiation to stream right through. Worse, if dropped, it can gouge or cut card surfaces. Yikes!
Museum Glass: Museum-grade glass uses optical coatings that eliminate up to 99% of incoming UV rays while virtually eliminating surface glare. It is, however, heavy, brittle, and fragile. Bumps or even vibrations can turn this frame into an internal guillotine for your most prized collectibles.
Standard Cast Acrylic/Plexiglass: Acrylic has excellent light transmittance (~92%) and is more impact-resistant than glass. However, standard acrylic frames only block about 40% to 50% of cumulative UV radiation.
Optical Polycarbonate: Polycarbonate is an ultra-tough synthetic resin used for bullet-resistant security glass and astronaut helmet visors.
Untreated polycarbonate is better at UV blockage than acrylic. When it’s synthesized with UV-absorbing additives, though, polycarbonate blocks up to 99.5% of harmful UV radiation. Crucially, polycarbonate’s impact resistance is roughly 250x greater than glass and 30x greater than acrylic.
Figure 2 – How Display Material Affects UV Blockage (Attenuation) by Material Type and Wavelength
This graph shows that Polycarbonate (PC) is a superior material for shielding your card from the harmful effects of sunlight (or even interior lights).
The graphic also highlights the extremely poor response of traditional glass against these harmful rays.
Polycarbonate > Acrylic >> Glass
Figure 3 – Card Display Material Comparison
This graph shows the relative merits of 4 different materials. The graphic shows the performance of those materials against 4 primary grading measures: UV attenuation (blockage), Drop Resistance, Handling Safety, and relative cost.
The polycarbonate material dominates in each category at the expense of a small amount of optical clarity.
Full disclosure: Polycarbonate does yellow slightly over time, affecting the optical clarity. This does not negate its protective qualities, however, as the card inside is not affected.
Polycarbonate is also safer to handle than other materials, and only slightly less clear
How do UV Blockers and Absorbers Work in Card Holders?
Don’t be afraid – we’ll keep it simple
How do we stop harmful UV Light? We can use an ingenious class of compounds known as Hydroxyphenyl-Benzotriazole UV Absorbers.
In budget display cases, manufacturers sometimes spray this on, but over time, it can wear off. For professional optical polycarbonate cases, however, UV-quenching molecules are compounded directly into the polymer resin melt prior to high-pressure injection molding.
NOTE: We don’t do this at Flippee to keep costs down (our product is not ‘museum grade’). But the inherent polycarbonate filtering is still provides superior UV protection compared to glass and acrylic
When an ultraviolet photon hits these absorbers, the molecule absorbs the photon and dissipates the energy as heat. The molecule then snaps back to its ground state in picoseconds, ready to absorb the next incoming photon millions of times over without degrading.
Measuring Ink Degradation
We can measure ink degradation from UV using these test methods:
1. UV-Vis Spectrophotometry – This passes light through the display and measures how much passes through at each wavelength
2. Accelerated Weathering Chambers (ASTM G154/ ASTM D4329) – These lab tests use standardized blue color tiles in a special weathering tester with high-intensity fluorescent UV lamps and high (60 Degrees C) temperatures to simulate years of natural sun exposure in a matter of days.
3. CIELAB Color Difference Spectrometry – This test quantifies how much color shifts as a result of UV exposure. The human eye can detect as little as a 2.0 color shift on this scale (see Figure 4).
Figure 4 – Ink Degradation vs. Material
This graph shows 4 common display materials and the color shifting effects for cards behind them (using the CIELAB method). The graphic shows, as expected, that glass is by far the worst at UV protection, acrylic is better, and polycarbonate protects the card from fading best.
The graph shows that while glass provides little UV protection, and acrylic slightly better, all perform better than no covering. This also shows that almost no solution can protect your cards completely from direct sunlight.
Even a small color shift can severely damage your trading card’s value
Conclusions and Recommendations
Conclusions
We have seen that polycarbonate provides the best protection for your card while providing ultra-clear visibility. This research led us to that conclusion and drives our desire to provide you with a frame suitable for your Most Valuable Card!
Stop hiding your treasures in a box! Flippee Brand products protect your card with polycarbonate while allowing you to see both sides of your card. The tough nylon case protects your investment, locks securely, and is tough enough to withstand the weight of a 4,000 pound automobile.
Flippee Brand Card Frames are Engineered to Protect your Most Valuable Cards
The Golden Rule: The Ultimate Card Display Room
Here are some tips for showing off your top cards and keeping them safe for years to come. Even with a top-tier card holder, the display environment separates the amateur from the museum-level curator. Follow these 3 rules for setting up your display space:
1.) Eliminate Direct Sunlight Paths – No Southern exposure, or west facing windows. Even UV protected cards are susceptible to thermal effects of direct sunlight including heating and drying of the cardstock
2.) Switch to LED Lighting – Fluorescent lights emit a lower, but still harmful, level of UV light. Save money and save your cards (Duh!)
3.) Maintain 45% Relative Humidity – Cardstock absorbs and releases moisture. Controlling your humidity keeps foil from warping and prevents microscopic mold development.
Thanks for your attention and I hope you enjoy YOUR cards for years to come …
References and Scientific Data Sources
ASTM International (2021). Standard Practice for Operating Fluorescent Ultraviolet (UV) Lamp Apparatus for Exposure of Nonmetallic Materials (ASTM Standard G154-16). West Conshohocken, PA: ASTM.
Feller, R. L. (1994). Accelerated Aging: Photochemical and Thermal Aspects. The Getty Conservation Institute, Research in Conservation Series. ISBN 978-0-89236-125-0.
International Organization for Standardization (2014). Textiles — Tests for colour fastness — Part B02: Colour fastness to artificial light: Xenon arc fading lamp test (ISO Standard 105-B02:2014). Geneva: ISO.
Library of Congress Preservation Directorate (2018). Specifications for Environmental Controls and Glazing Materials in Paper and Document Display Cases. Preservation Research and Testing Division.
Ranby, B., & Rabek, J. F. (2012). Photodegradation, Photo-oxidation and Photostabilization of Polymers: Principles and Applications. John Wiley & Sons, New York.
Thomson, G. (1986). The Museum Environment (2nd ed.). Butterworth-Heinemann Series in Conservation and Museology. Oxford, UK.