Belgian software outfit Kubuz has launched 3dSynth, a free, browser-based design workspace that builds toolpaths and G-code for FDM printers directly, without routing a model through a conventional slicer first. The pitch is unusual for a maker tool: instead of designing a mesh and handing it to a slicer to figure out perimeters, infill and Z-hops, 3dSynth lets users construct the print motion itself, then generates machine code straight from that description — a workflow aimed squarely at vase-mode, spiral and other single-wall or generative prints where a slicer's standard toolpath logic is often more obstacle than help.
The tool runs entirely in the browser. Kubuz's own product page describes it as "free to tinker, no account needed, runs in your browser," and the company frames the whole approach with a tagline that doubles as a thesis statement: "Shape the print, not just the mesh." That distinction matters to anyone who has fought a slicer's seam alignment or spiral-vase settings trying to get a smooth, structurally sound single-wall print — 3dSynth's premise is that if you control the toolpath generation from the start, you don't have to fight anything.
Nine Modules, One Workspace
3dSynth ships with nine design modules in its free tier, according to the product's own listing: G-code Sculptor, Node Sculptor, SynthBlocks, Mesh Sculptor, Texturize, Custom G-code, Fabric Sculpt, Hex Grid and Predefined Models. That spread covers a lot of conceptual ground — some modules read as direct toolpath authoring tools (G-code Sculptor, Custom G-code), others as procedural/parametric mesh generators (Node Sculptor, SynthBlocks, Hex Grid), and Texturize and Fabric Sculpt suggest surface-pattern and lattice-like generation aimed at the vase-mode aesthetic that's become a small subculture of its own on printing forums and Etsy shops alike.
Kubuz's site also lists "hundreds of machine profiles" and a real-time 3D preview that shows nozzle travel and seam placement before anything gets sent to a printer — a genuinely useful sanity check for a workflow where the toolpath, not the mesh, is the primary design surface. Getting the seam and travel moves wrong in a generative or spiral print is much more visible than in a normal multi-wall object, since there's no infill or extra perimeters to hide a mistake, so previewing exactly where the nozzle goes before committing filament to it is a reasonable feature to lead with.
Critically, 3dSynth isn't a slicer replacement for every job — it's a parallel path for the kinds of prints where slicers are a poor fit. The tool still exports standard mesh formats like STL — confirmed both by VoxelMatters' reporting and by Kubuz's own site, which names PrusaSlicer, Cura and Bambu Studio specifically — so a design built or refined in 3dSynth can be handed off to any conventional slicer when a project calls for normal multi-wall, multi-material printing instead of direct toolpath generation.
Free Tier vs. the $39 Premium License
VoxelMatters, which published its report on September 24, 2026, and credits the tool to "Dennis from Kubuz," lays out the split between the free and paid tiers in more detail than Kubuz's own marketing page. The free version caps the G-code Sculptor module's exports at a two-effect stack — enough to explore the concept and produce simple output, but limited for anyone stacking multiple procedural effects into a single complex toolpath.
A one-time $39 Premium license, sold through Gumroad rather than a subscription, removes that cap and unlocks unlimited effect stacks. It also adds SynthBlocks export to G-code, STL, OBJ and glTF; project saving (the free tier appears to be session-based, per Kubuz's "no account needed" framing); a line-by-line G-code inspector; commercial use rights; and an offline desktop app for Windows, macOS and Linux. That last item is worth flagging for anyone leery of browser-only tools for production work — a local desktop build means the workflow doesn't depend on a live web app staying online, though as of launch that build is gated behind the paid license rather than included free.
VoxelMatters also notes a disclaimer from Kubuz that's worth taking at face value given how many machine profiles the tool ships with: the company says it isn't affiliated with any printer manufacturer, and that the "hundreds of machine profiles" are used only to generate G-code compatible with a given printer — not that Kubuz has any formal partnership or certification arrangement with those brands.
What It Means for Makers
The interesting bet here isn't that 3dSynth will replace Cura or PrusaSlicer for everyday multi-part, multi-material jobs — it clearly isn't built for that, and its own export path back to STL concedes as much. The bet is that a meaningful slice of what people print on FDM machines — vases, lamp shades, decorative spirals, generative lattice objects, single-wall parametric shapes — is currently being forced through slicer settings (spiral vase mode, variable layer height hacks, custom Z-hop tuning) that were designed for structural, multi-wall parts and only sort of work for those cases. Designing the toolpath directly, rather than reverse-engineering one out of slicer settings, is a legitimately different approach to that problem, and the zero-cost, no-install browser entry point makes it trivial to find out whether it's useful for your own prints before paying anything.
The practical calculus for most makers will come down to the free tier's two-effect cap in G-code Sculptor. Anyone doing a one-off spiral vase or testing whether procedural toolpath design is worth learning can do that entirely for free. Anyone building a repeatable production workflow — say, a small Etsy shop churning out textured vases — will likely bump into that limit fast and face the $39 Premium decision, which is a low bar compared to most CAD or slicer add-on pricing, especially given it's a one-time purchase rather than a subscription. Whether the nine modules hold up to sustained use, and whether the real-time preview stays accurate on more complex node graphs, are things only hands-on testing will settle — but as a free, no-account way to try an actual alternative to slicer-driven vase and spiral printing, 3dSynth is a low-risk experiment worth a maker's afternoon.
