Knucklebone - Ultem Our new Ultem knucklebone line features the original shape and size, our new slimini design, and a middle grip for the modular setup. Ultem is slightly heavier than acrylics, but in its polished finish, it has much the same feel. Both the original and the slimini come polished, which improves grip during manipulation. This can be helpful in cold/ dry weather, and is useful for moves that involve manipulating the knucklebones from the end grips. For something a little different, we're offering the modular middle grips with a machine finish, which reduces friction against the skin, allowing kbone setups using this grip to roll easily and smoothly between the fingers. Black Ultem Through our amber ultem adventures, we’ve found that the ultem material takes on an amazing feeling frosted finish when sandblasted, and the same holds with black ultem. As the first successor to our Black Ultem Kickstarter, we’re able to offer a limited batch created from the remaining campaign stock, but these are not here to stay. Once this batch is depleted, that's a wrap for the foreseeable future so be sure to pick one up before it’s too late! The blasted black ultem material has a unique appearance, almost resembling blasted titanium, but with a velvety soft feel that just makes the Knucklebones absolutely dance through the fingers. Unlike polished or even machine finished polymer materials, the sandblasted ultem does not grip or bind to the skin, allowing it to smoothly glide from position to position. While the finish starts out with a dusty grey colour, it quickly deepens and darkens to a frosted black through play. For those who prefer a sleeker look, the polished black ultem offers a striking alternative. Where the blasted version opens with a dusty grey and darkens into a frosted black, the polished version starts deep and stays deep with a rich, glassy black with a smooth, almost liquid surface. The polished finish gives the material a denser, more substantial visual presence, and catches light in a way that highlights the Knucklebones' geometry with clean, sharp definition. The feel underhand is equally smooth, with the inherent catching nature of polished ultem lending a fluid, effortless quality to movement through the fingers. Two finishes, same exceptional material — the choice comes down to whether you prefer your black matte or mirror. Amber Ultem Ultem is the branded name for a high-performance polymer also known as polyetherimide, or PEI. It's solidly in the category of what we might call badass plastics. These are materials that demonstrate exceptional properties, which truly set them apart from conventional polymers. Ultem has actually been around since the 1980s, but has only recently become widely commercially avaiable, and has subsequently exploded into the EDC scene. You'll see it in everything from knife handles to flashlights and everything in between. Part of what makes Ultem special is that when it sets and solidifies, the polymers bond in a way that prevents re-melting, even under extreme heat. This gives the material excellent thermal properties. It's also UV, chemical, and flame resistant, and due to its hardness, it can be machined very precisely, and much thinner than other plastics. Strictly speaking, none of these properties are required for a set of beads, but as with titanium on kevlar, there's just something awesome in knowing that what you have in your hand is exceptional.. that you could, if you wanted, use it for aerospace applications. The material has a crisp and solid feel in the hand. The polished versions have a glossy texture, similar to acrylic, while the machined finished versions have a soft feel, almsot like sea glass. To most collectors and EDC enthusiasts, the most distinctive feature of Ultem might be its appearance. It is truly something to behold. In its natural state, the material is clear or semi-transparent, with a deep golden yellow or amber colour. In fact, it looks and feels remarkably like an amber resin, and there is an interesting connection there that is worth elaborating. Amber is one of the traditionally prized materials used for komboloi and worry beads, throughout the Mediterranean and Middle East. And while we often think of traditional materials as being those that are naturally occurring, this is not entirely the case with worry beads. Amber itself is often stabilized with synthetic resins, but beyond this, readers of bead history will also see frequent reference to exotic sounding materials like Faturan, Bakelite, Parkesine, and Catalin. These are all polymer plastics - prized by antique collectors, and still used today in modern production. This historical context helps to legitimize a higher end polymer like Ultem in our product range, and in some ways, it's kind of symbolic of our journey. One of this things Aroundsquare has done well as a brand over the years is to respect and build on the historical roots of the products we create, and extend them into the modern era. We always seek to recognize and honour these roots, while bringing out contemporary designs using the best available modern materials. And having said all of that, here's this month's Ultem lineup. Details Finishes: Black Ultem - Sandblasted Black Ultem - Polished Amber Ultem - Polished Weight: ~ 12.7g Length: 60mm For a hands on look at the Black Sandblasted Ultem Knucklebone, checkout the May 2026 launch video! For more information on Aroundsquare's Kbones, visit the Knucklebone product page.
