We’re clearly in the minority when it comes to the choice of crystal we use in our watches. While many prefer sapphire, we’ve opted for old-school Hesalite (or plexiglass, or simply acrylic). Why do we love it? In short, it's more visually pleasing (clearer, warmer, less reflective), harder to break/shatter (more tool-ish), and more authentic to the spirit of a mid-century sports watch.
Regardless, we do get a lot of inquiries, so read on for our responses to the most common questions we’ve gotten on the topic:
Why would I buy a watch with a plastic crystal, when I could get sapphire for the same price or less?
Believe it or not, it’s not about cost. It’s about recreating a certain magic that vintage watches had. As the very lens through which one views the dial and hands, the crystal is essential to this. The optical quality of Hesalite allows a watch to "pop" more, because it has much less glare than sapphire's cold, mirror-like finish.
To even come close to re-creating the bubble-like look of Hesalite, sapphire would need antireflective coating on both the inside and outside surfaces of the crystal, which would defeat the purpose of its scratch resistance.
But isn’t sapphire an upgrade? I want something with vintage looks, but with tougher, modern materials.
We’ve always thought that Hesalite gets a bad rap on its toughness, and this may have to do with how we view watches. In today’s context, they’re mostly used as accessories/jewelry, so of course, the priority would be to keep them looking pristine.
But back then, they were used as tools, so the focus was different. For instance, look at these icons with plastic crystals.*
Photo credit: Hodinkee
"Military specifications mostly left the choice of glass up to the makers, only noting that an 'approved unbreakable type' should be used. Typically, plexiglass or acrylic crystals were used on military watches. Both materials provided an advantage over sapphire as they would crack rather than shatter, making them more durable."
While sapphire is harder, it’s also more brittle. Plastic’s flexible nature makes it easier to scratch, but harder to break. If it does, it cracks rather than shatters, so there won’t be loose shards that could harm the dial and movement. Besides, if you do scratch plexi, it’s extremely easy to polish—it's the only material for a crystal where scratches don't have to be permanent.
It's that easy: scratches before and after a quick application of Polywatch.
I feel like you’re just saying all this as a way to cut costs and maximize profit.
That’s OK! We've gotten this comment before, and even though plexi does cost us more, just stating that fact hasn't proven convincing to most people.
At this point, our goal isn’t to convince you, but to explain why we do what we do as best we can. Not many of us have access to vintage sports watches, so it's always difficult to translate what makes them special. There’s a reason why Omega still makes the Speedmaster with a plastic crystal, and Sinn their Flieger chronographs (103 and 356)—and these are watches that cost much more.
With every manufacturer we went to, a flat sapphire cost less than a truly vintage-style dome plexi, especially in small-batch, specialized manufacturing (for instance, here’s an acrylic crystal that costs $250). Modern “double dome” sapphire crystals are affordable, but barely curved, as you can see in the comparison below:
A modern double dome sapphire.
Photo credit: Two Broke Watch Snobs
A vintage plexi dome.
Photo credit: Phillips
Don't just take our word for it:
"If you know the look of a big bubble on an old dive watch, that's what you get with hesalite (which is acrylic)...even box section sapphires that try to emulate that look, they don't quite achieve the same look. You've either got thermoplastic, or you don't."
In sum, we love Hesalite because it allows us to time travel a little bit. But it's not only for the sake of nostalgia, not just to call back to an era of watches as instruments. On its own, it still looks fantastic and is still extremely practical. It's just as good now as it was back then.
Rolex’s use of acrylic vs. sapphire is a good example of this. As they shifted from tool watches to the high luxury market in the 1970s and 80s, they transitioned to using sapphire instead of acrylic crystals. They still had stragglers though: their most toolish models, the no-date Submariner and the Rolex Explorer, had acrylic crystals until 1990.