Working in three dimensions: additive and subtractive processes, modelling, construction and casting, working with clay, card, wire and found materials, and thinking in form, space and material.

What this dot point is asking

Working in three dimensions means making form in real space, and it uses a different set of processes and a different way of thinking from flat work. This dot point is about the main 3D processes: additive and subtractive methods, modelling, construction and casting, the materials (clay, card, wire, found objects), and thinking in form, space and material. Choosing and refining a 3D process is an AO2 decision, and seeing in the round is a recording (AO3) and outcome (AO4) skill.

Additive and subtractive processes

The most fundamental distinction in 3D work is between adding and removing material. Additive processes build up form: you add material to grow the piece, as in modelling clay, constructing with card and wire, or casting (filling a mould). Additive work is forgiving and exploratory, because you can add, join and rework as you go. Subtractive processes remove material to reveal form: you carve away from a block (plaster, soap, wood) until the form emerges. Subtractive work is committing, because every cut is permanent and you cannot put material back, so it demands a clear plan before you start.

Modelling, construction and casting

The additive family covers three main methods. Modelling shapes a soft, pliable material (clay, plasticine, papier-mache) by hand or with tools, adding and refining form directly, and it suits organic, sculptural shapes. Construction joins separate elements (card, wire, wood, found objects) into a structure, suiting linear, architectural or assembled forms. Casting fills a mould with a fluid material (plaster, jesmonite) that sets into the mould's shape, letting you reproduce a form or capture surface detail. Each gives a different kind of result, so the method is part of the idea.

Materials and their behaviour

Materials behave differently, and the choice shapes the work. Clay is soft and plastic, good for modelling organic form, and it can be fired into permanent ceramic. Card is light, flat and easily cut and folded, good for construction and quick maquettes. Wire is linear and flexible, good for drawing in space and armatures (the internal frame inside a modelled or built form). Found materials carry their own associations and textures, useful for assemblage with meaning. As with all media, choose the material whose behaviour suits the idea, and test it before committing, which is the AO2 explore-and-select pattern in three dimensions.

Thinking in form and space

The deepest shift in 3D work is thinking in space as well as form. A flat drawing is read from one viewpoint, but a 3D piece is read in the round, from every angle, so it must work from all sides, not just a "front". It also occupies and shapes space: the spaces within and around it (negative space in three dimensions), how it sits in its setting, and how a viewer moves around or through it are part of the work. So when you design and make in 3D, consider every viewpoint and the space the piece creates, because these are part of its visual language.

Try this

Q1. State the difference between additive and subtractive processes, with an example of each. [Knowledge recall]

• Cue. Additive processes build up form by adding material (for example modelling clay or constructing in card and wire) and are reworkable; subtractive processes remove material to reveal form (for example carving plaster or wood) and are permanent, so they demand planning.

Q2. Explain why working in three dimensions means thinking about space as well as form. [Short explanation]

• Cue. A 3D piece is a solid form read in the round from every angle, not from one viewpoint, and it also occupies and shapes space: the negative spaces within and around it, its setting, and how a viewer moves around it are all part of the work, so both the form and the space it creates are part of its visual language.