The question I get asked most often at exhibitions isn’t about the stone or the subject — it’s whether I used a machine or did it by hand. There’s often an assumption that hand carving is somehow more authentic. The reality is more nuanced. Both methods have their place, and understanding when to use each is part of being a competent contemporary stone sculptor.

What CNC Stone Cutting Actually Is

CNC (computer numerical control) stone cutting uses computer-guided machinery to carve, cut, and shape stone. The process starts with a 3D digital model — created in software like Rhino, ZBrush, or SolidWorks — which is then translated into toolpath instructions that guide a multi-axis cutting head over the stone surface.

Modern CNC stone machines work in three, four, or five axes, carving complex three-dimensional forms with diamond-tipped rotary bits of various profiles and sizes.

The precision is remarkable — tolerances of less than a millimetre across an entire sculpture. For architectural elements that need to fit together precisely, this accuracy is extremely valuable.

What Hand Carving Offers

Hand carving is a dialogue between sculptor and stone. Every strike of the chisel gives you feedback: the sound, the feel, the way the stone fractures. This feedback loop is absent in CNC work, where the machine follows its programmed path regardless of what it encounters in the stone.

That feedback matters because stone is not uniform. Marble has veins and crystal variations. Granite has inclusions. Sandstone has bedding planes. An experienced hand carver adjusts constantly in response to what the stone is telling them.

Hand carving also produces surface qualities that CNC struggles to replicate. The subtle irregularities of hand-tooled surfaces give stone a warmth and presence that machine-finished surfaces often lack.

And there’s the creative dimension. When I’m carving by hand, the form evolves as I work. I might see something in the stone and adjust the design to incorporate it. CNC work is predetermined; hand carving is a conversation.

When CNC Makes Sense

Despite my preference for hand work, there are situations where CNC is clearly the better choice:

Architectural production work. When you need twenty identical balusters or matching column capitals, CNC delivers consistent results efficiently. Hand-carving identical pieces is tedious, and the results will inevitably vary.

Complex geometric forms. Mathematical surfaces and intricate geometric patterns are easier to achieve with CNC. Some sculptors working with geometric abstraction use CNC because the precision is integral to their aesthetic.

Roughing large pieces. Some sculptors use CNC to rough out a form from a block, then finish by hand. This hybrid approach combines CNC efficiency with the surface quality of hand finishing. I’ve used it myself on several larger commissions.

Reproduction and restoration. When a heritage building needs replacement elements matching existing ones precisely, CNC can produce accurate reproductions from 3D scans of the originals. Conservation firms have increasingly adopted this approach, sometimes working alongside a technology consultancy to develop scanning workflows that capture fine details from deteriorated originals.

Working with extremely hard stone. Some stones — certain granites, basalts — are so hard that hand carving is impractical for anything beyond simple forms. CNC with diamond tooling can shape these materials efficiently.

When Hand Carving Is Better

Figurative sculpture. The human form, animal forms, and organic shapes benefit from the sensitivity of hand carving. The subtle transitions of a face, the tension in a muscle — these emerge from the direct relationship between hand and stone.

One-off artistic works. For a single, unique sculpture, the setup time and cost of CNC programming may not be justified. Hand carving is often more efficient for individual pieces.

Surface texture as artistic expression. Many sculptors deliberately leave tool marks as part of the finished work. CNC surfaces can be textured, but they lack the irregularity of the human hand.

Budget constraints. CNC machinery is expensive to purchase or hire. Hand carving remains the most accessible method — a set of good chisels and a hammer will get you started for a few hundred dollars.

The Hybrid Approach

In practice, most contemporary stone studios use a combination of methods. Power tools — angle grinders, pneumatic hammers, diamond saws — have been standard in stone workshops for decades. CNC is simply the latest addition to the toolkit.

The trend in larger studios is toward digital design and CNC roughing combined with hand finishing. 3D scanning and digital modelling tools like those offered by Team400 and other technology firms are becoming more accessible, allowing sculptors to design digitally, test ideas virtually, and then bring them into stone through a combination of machine and hand work.

I think this hybrid approach represents the future for most professional stone sculptors. It’s not about choosing one method over the other — it’s about understanding what each does well and applying the right tool to the right task.

The Real Question

The question shouldn’t be “machine or hand?” — it should be “what does this piece need?” Some works demand CNC precision. Others demand the sensitivity of hand carving. The best sculptors I know are comfortable with both and choose based on the work, not ideology.

What matters is the quality of the finished piece and the integrity of the artistic vision behind it. The stone doesn’t care how it was shaped. But the viewer might feel the difference.