Volumetric additive manufacturing — printing an entire object at once instead of layer by layer — has spent years as a lab curiosity that makers could read about but not actually build. That may be changing. According to Hackaday's July 7 coverage, the open-source OpenCAL project has released its V2 hardware this summer and disclosed that it is in talks with Formlabs to manufacture the specialized photosensitive resin the process depends on, aiming for far cheaper material than the specialty-chemistry pricing that has historically put volumetric printing out of reach for hobbyists. Hackaday's report does not cite a specific price target.
It's a small line in a bigger story, but it addresses the piece of the volumetric-printing puzzle that hardware hackers can't solve themselves: chemistry supply.
What CAL Actually Does
Computed axial lithography, the method OpenCAL implements, doesn't build parts the way an FDM or standard resin printer does. Instead of depositing or curing material one thin slice at a time, CAL rotates a vat of liquid photopolymer resin while projecting a sequence of light patterns into it from a fixed direction. Each pattern accumulates a dose of light energy at every point inside the resin as the vat spins, and the printer computes the projected images so that only the voxels corresponding to the final object ever cross the resin's curing threshold. Everywhere else, the light dose stays sub-threshold and the resin never gels.
Hackaday describes the underlying math as built on reverse-tomography principles: instead of reconstructing a 3D volume from a stack of 2D projections the way a CT scanner does, CAL synthesizes a stack of 2D projections that reconstructs into a specific 3D solid when beamed through a rotating, curable medium. The practical upshot is that the entire object solidifies in place at once, all its layers "finishing" together rather than sequentially — which is why proponents describe CAL prints as taking minutes rather than the hours typical of FDM or layer-by-layer resin printing.
OpenCAL itself isn't new. As Hackaday has reported, the project traces back to CAL research UC Berkeley released as an open-source system around 2019, work that remained too expensive and complicated for hobbyists at the time. As Hackaday noted in an earlier June 14 background piece, OpenCAL's mission has been to turn that lab-grade research build into something the public can construct, run, and modify — machine, software, and resin sourcing included, now backed by full documentation and a GitHub repository rather than just a Discord server. A consumer-oriented prototype using a standard projector and common hobbyist electronics was shown at Open Sauce in 2025, and the V2 hardware released this summer refines that goal further — the kind of mechanical and optical build a hobbyist could plausibly assemble on a bench rather than in a university photonics lab.
Three Barriers, and Why Resin Was the Stubborn One
Hackaday's framing of the story is useful because it names the obstacle set plainly: hardware, software, and materials. Hardware has been the most visible barrier and the one open-source projects are best equipped to chip away at — precision rotation stages, projectors, and vat optics are the kind of problem hobbyist engineering communities solve iteratively, and OpenCAL's V2 is evidence of that progress. Software has been the second barrier; Hackaday reports OpenCAL is now pairing its hardware with new standalone control software called Tomo, aimed at letting people run an OpenCAL printer — or in principle any other volumetric-printing hardware — with little technical expertise.
Resin has been the stubborn one, and for a structural reason rather than a merely commercial one. CAL resin isn't interchangeable with the resin in an MSLA printer's vat. Because the entire volume needs to sit just below its gel point until the cumulative light dose from every angle pushes the targeted voxels over the threshold, the photoinitiator chemistry has to be tuned for a very different dose-response curve than resins designed for point-by-point curing under a single UV pass. That specialized chemistry, produced at hobbyist-relevant volumes by nobody in particular, is what has kept CAL resin priced far above ordinary MSLA resin — and kept the barrier to entry high even for makers who could build or buy the hardware.
That's the gap Formlabs' involvement is aimed at closing. Formlabs already runs resin formulation and manufacturing at a scale most open-source hardware projects can't approach on their own, and Hackaday reports that talks between the OpenCAL team and Formlabs are working out an arrangement to produce this specialized resin for far cheaper than what's available today. Hackaday's coverage does not specify a dollar figure or a delivery date.
What It Means for Makers
None of this means volumetric printers are about to show up next to Bambu and Prusa machines on maker benches this year. OpenCAL remains a project you build, not a product you unbox, and the Formlabs resin arrangement is described as being worked out rather than finalized and shipping. But the shape of the barrier is changing in a way worth tracking. Until now, a maker curious about CAL faced three simultaneous problems: sourcing or building precision rotating-vat hardware, writing or adapting projection-sequence software, and finding resin that wasn't priced for a university lab's grant budget. OpenCAL's V2 chips at the first problem, Tomo chips at the second, and a Formlabs-manufactured resin at meaningfully lower cost than today's specialty CAL chemistry would chip at the third.
If that cheaper resin materializes, the practical case for CAL sharpens considerably: full-object cures measured in minutes instead of the hours FDM or layer-by-layer resin printing demand, with no layer lines to sand or support structures to plan around, since nothing is built up incrementally. Whether that's enough to pull volumetric printing out of the research-project category and into the hobbyist toolkit will depend on things Hackaday's reporting doesn't yet resolve — the actual resin price once the Formlabs arrangement is finalized, how accessible Tomo turns out to be for non-specialists, and how reproducible V2 builds are for makers without a background in optics. Hackaday's coverage also flags open practical questions even with the hardware in hand, including how to remove partially cured resin from a finished print and how to tell when a print is actually done. But for a technology that has spent most of its existence as a demo video from a university lab, having a commercial resin supplier at the table is a genuinely new development.
