Arc & Sparo Studio
Process Journal — Form, Texture, and Geometry
Work in progress, Notes from the Studio
Geometry has a way of revealing both the discipline and the patience of the maker.
This week in the studio, I’ve been refining a series of textured plaster molds — part of an ongoing exploration into precision, pattern, and process.
The pattern I’m working with here is called Cubical: a tessellation of interlocking cubes that plays with light and shadow in subtle, shifting ways.
The master mold in perspective. Every edge feels deliberate here — a quiet structure waiting for its first casting.
Plaster mold-making seems deceptively simple, but success depends on a deep respect for detail — geometry, timing, and patience all have to align.
These notes capture some of my ongoing learnings and objectives in the process.
Objective 1 — Seamlessness
The first aim: achieve a near-invisible joint between adjoining mold pieces.
In Cubical, the right-angle seam closes with a faint trace — a satisfying success.
Whether the master mold is CNC-machined or 3D-printed (as in this case), geometric tolerances matter: flatness, perpendicularity, parallelism, and dimension all need to align within fractions of a millimeter.
True precision here isn’t about chasing perfection for its own sake — it’s about creating forms that disappear into continuity.
Two mold pieces meeting near-seamlessly at a right angle — the satisfaction of alignment. When every edge lands where it should, the geometry feels calm, resolved.
Objective 2 — Surface Clarity
The second goal is achieving pristine surface detail — bubble-free plaster castings.
Tiny air bubbles in the mold become raised spheres on the clay body, requiring clean-up.
To minimize air bubbles in plaster molds, I experiment with several approaches:
- Vacuum mixing — eliminating bubbles before pouring.
- Mechanical agitation — vibrating the mold after pouring.
- Pressure-chamber curing — compressing the mix once inside the mold.
Each has trade-offs between cleanliness, control, and practicality.
Vacuum mixing (as used in the dental field) produces clean slurries, but sharp topographies in the mold can still trap air (even with mechanical agitation).
I have yet to try pressure-chamber curing, which I believe will give the cleanest results.
When specialized tools aren’t available, design itself becomes the solution — gentle curves and blended surfaces should reduce trapped air with a bit of agitation.
A perfect plaster mold is an elusive thing. In this batch, I achieved good seam alignment, but a few small bubbles remain — reminders that technique is iterative, not static.
A rhythm of repeating cubes in plaster. The pattern catches light differently from every angle — crisp, quiet, deliberate.
Objective 3 — Clean Release
A successful mold release is one of those moments that feels effortless only after much effort.
Rigid master molds, like the one I've made for this study, don’t always forgive impatience.
Silicone would be ideal, but here time and pragmatism called for a stiff resin material.
A light mist of release agent helps separation; too much, however, creates surface ripples in the plaster.
Drying time matters, and patience is essential: if plaster is pulled too early, it clings and leaves behind deposits that mar the master mold.
Impatience leaves its mark. I pulled the plaster too early, and it clung to the master — a small but valuable lesson in timing and restraint..
Where rigid molds must be used, draft angles and fillets ease release and preserve surface fidelity.
Precision is not only in mold-making — it’s in timing, restraint, and understanding how materials choose to part ways.
Failures as Guides
Not every release succeeds.
One of the castings below split in two during demolding — a result of friction and suction in the mold’s geometries.
Failures like this are important data points — a physical note that says, adjust here.
A few clean releases, one split in two. The break came from the mold holding on a little too tightly. A small failure, but also a moment of learning — knowing when to let go, when to hold, and how to make both look effortless.
Reflection
Every plaster mold records its own making.
It remembers vibration, air, and impatience.
It holds the invisible conversation between geometry and chance.
This process of making plaster molds sits somewhere between control and surrender — between the precision of design and the unpredictability of matter.
There’s a kind of beauty in that negotiation, in learning where to stop forcing and start listening.
Cubical is part of an ongoing pursuit — to understand how light, form, and surface can meet with quiet accuracy.
These molds won’t just shape clay; they shape how I think about texture, precision, and the invisible craft behind seamless design.