When upgrading your Seiko watch crystal, the most important choice you'll arguably make is choosing the type of material to go with (which we highly recommend to be sapphire, by the way). The next most important factor is which type of anti-reflective (AR) coating to choose.

Sapphire crystals last longer and are more scratch resistant than mineral crystals, but glare can still be an issue without the right AR coating. Imagine having to roll your wrist a couple different ways, or cupping your hands over your watch just to be able to tell what time it is when you’re under broad daylight - you don’t want to be that guy.



So which AR coating is right for your Seiko mod? Read on as we cover the key differences between the AR options and provide crystal upgrade considerations for your unique needs and style.

Outer vs. Inner AR Coating

When reviewing AR coatings for watch crystals, you’ll notice they come in either outer or inner varieties. Outer coatings are applied on top of the crystal, leaving them exposed. Inner AR coatings are applied underneath the crystal, pressing up against the dial side.


Source: Botta Design


Outer coatings have the advantage of being easier to apply and marginally better at glare reduction due to increased layering. However, inner coatings are significantly more durable since they avoid day-to-day scrapes and exposure to the elements. An outer coating would quickly degrade in quality after hitting a door frame or through moisture and sweat contact over time.

Our inner AR coatings are securely sealed between the crystal and watch dial, keeping them pristine. This provides long-term glare reduction without compromising coating integrity.


Single vs. Multiple AR Coatings

Anti-reflective coatings work by using thin film interference to cancel out specific light wavelengths that cause glare and reflections. Single AR coatings cancel out a portion of light, while multiple coatings block wider bands of wavelengths for better effect.


Source: @brionbonk from Reddit


Double coatings come at nearly twice the price of single coatings however. You'll need to decide if the additional glare reduction is worth the cost based on how you use your Seiko watch. Those constantly outdoors or in low light conditions find the upgrade worthwhile.


Choosing between a single or double coating often comes down to lifestyle and budget. But we also offer coatings tailored to specific use cases. Our clear AR is versatile for everyday wear, while colored blue and red AR coatings provide functional advantages.


Clear AR Coating

A colorless, transparent AR coating is the most popular choice and suits most watch enthusiasts' needs. Our clear coating reduces glare for easy dial readability without altering the watch's intended design.



This versatile option works well in nearly all environments. The only downside to clear AR is that it shows fingerprints and smudges more easily due to the crisp light diffusion.


Red AR Coating

Red anti-reflective coatings heighten contrast, improving readability where it counts most - in low light situations. The subtle red tint filters blue light wavelengths, resulting in sharper dial presentation in shaded conditions.


Source: @caseanddial on IG


As an added bonus, the red hue is only perceptible at sharp viewing angles making it a subtle addition to the crystal. Head-on, a red AR coated crystal faces no aesthetic compromises.


Blue AR Coating

On the opposite end of the light spectrum, blue AR coatings excel in bright, sunny environments. Blue light wavelengths are filtered out rather than red. This reduces eye strain and sharpens visibility where glare typically overwhelms.



Blue AR is especially popular with divers and aquatic enthusiasts thanks to maximize readability through sea reflections. The blue tint faces no stealth or stylistic compromises.

Wrap Up

Installing an AR coating requires care and precision to ensure the crystal's clarity and longevity. Seek out an experienced watchmaker to handle the installation. Their expertise preserves the coating while properly sealing the crystal. Or better yet, you can get one of our crystals that already come with AR coating pre-added for less hassle. We have crystals available for the SKX007, SRPE 5 Sports, SRP Turtle, and more! 

Caring for your AR coating is also important especially if your crystal's coating is on the outside. Use microfibre cloths and mild soap to gently clean the crystal, removing fingerprints and smudges without damaging the delicate coating. With proper installation and care, your AR-coated crystal will maintain its glare-reducing capabilities.

An AR coating unveils a new dimension of your Seiko mod by amplifying its inherent qualities. More than a practical upgrade, it's a way to customize the look and feel of your timepiece. The coating you chose reflects your style and personality.

January 13, 2024 — Jeremiah A

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