PSEB Class 12 Modelling & Sculpture cheat sheet

Indus Valley (c. 2500 BCE): the bronze Dancing Girl from Mohenjo-daro is a lost-wax cast with a bangle-covered arm and hand on hip; the steatite Priest-King bust and thousands of mould-made terracotta figurines and seals come from the same sites.

Mauryan (c. 322–185 BCE): Chunar sandstone worked to a mirror polish; Ashokan pillars carry animal capitals (Sarnath four-lion capital, Rampurva bull); the Didarganj Yakshi holds a chauri and shows strict frontality.

Sunga (c. 185–73 BCE): Bharhut railing reliefs in red sandstone with yakshas, lotus medallions and inscribed Jataka labels; Sanchi balustrades continue the low-relief, flat-ground convention.

Kushana (1st–3rd century CE): two schools run in parallel - Mathura uses mottled red sandstone with indigenous Kushana royal portraits and shaved-head Buddhas; Gandhara uses grey schist with Greco-Roman wavy hair, heavy drapery and contrapposto.

Gupta (4th–6th century CE): the classic phase; the Sarnath Buddha in Chunar sandstone has transparent clinging drapery and a decorated halo, the Sultanganj bronze Buddha shows mature metal casting, and Udayagiri yields the colossal Varaha relief.

Medieval: Ellora and Khajuraho (Chandella) exploit high relief and deep undercutting; Konark (Eastern Ganga) uses tiered chariot wheels; Hoyasala carvers work soft soapstone at Belur and Halebidu; Chola workshops cast Nataraja bronzes by cire-perdue.

Folk and living traditions: Panchmura/Bankura terracotta horses, Bastar and Dokra bell-metal lost-wax figures, Kondapalli light wood carving, Molela terracotta relief plaques - all use local clay, wax, sawdust or softwood.

Decision rule for identification: read material + surface finish + drapery treatment + hair and facial type + posture. Subject alone (a Buddha, a yakshi) does not fix the period or school.

Clay is water-based: keep it plastic wrapped in polythene with a damp cloth, reclaim by drying, slaking and wedging, join only at leather-hard stage with slip, and never patch dry clay onto wet - the shrinkage difference cracks the join.

Plaster of Paris is mixed by sifting plaster into water, not water into plaster; normal mould consistency is about 2 parts plaster to 1 part water by weight; setting is exothermic and set plaster must never go down a sink.

Armature: aluminium or galvanised wire, rod or pipe, with a wooden cross for a figure; it must sit slightly inside the intended surface, and any standing figure over about 20 cm needs a pipe armature tied to the modelling stand.

Core implements: wooden modelling tools for blocking masses, wire-loop tools for removing clay, kidney and steel scrapers for compressing planes, sponge and water for smoothing, dividers and calipers for measuring.

Wax: paraffin or microcrystalline wax softened with beeswax, melting around 60–70 °C; melt in a double boiler, never over open flame, and keep below smoking point.

Stone: point chisel for roughing, claw chisel for levelling, flat and bull-nose chisels for shaping; carve downhill with the grain of the form to avoid spalling, and clamp the block rather than holding it by hand.

Wood: gouges and mallet, cut along the grain, expect short-grain tearing at ends; green wood shrinks and splits, so seasoned stock is preferred for carved work.

Metal: repoussé works the sheet from the back, chasing refines the front, annealing restores workability after hammering, brazing joins sections; pickle and flux fumes need extraction.

Safety rules: P2/N95 respirator for silica, clay and plaster dust, goggles when chiselling, nitrile gloves for epoxy, resin and shellac, wet methods to suppress dust, no food or drink at the bench, water kept away from plaster bins and electrical turntables.

Canon: the adult standing figure is about 7 to 7.5 heads tall, head height measured crown to chin; shoulder breadth is roughly one quarter of total standing height.

Head landmarks: eye line at the vertical midpoint of the head; hairline-to-brow, brow-to-nose-base and nose-base-to-chin divide the face into thirds; the mouth line sits about one third of the way up from chin to nose base; ears run from brow line to nose base; the gap between the eyes equals one eye width.

Block-in order: gesture and axis lines, then simple masses (cranium as sphere, ribcage as egg, pelvis as box), then planes, then detail; advance the whole figure together rather than finishing one part first.

Measurement: drop a plumb line from the pit of the neck and from the ear to check stacking over the supporting foot; use dividers and calipers for widths and depths, then confirm by eye before cutting.

In-the-round discipline: rotate the stand at every stage and judge front, three-quarter, side and back silhouettes; a figure modelled only from the front fails the profile test.

Life-room control: set the model at eye level at a fixed distance, mark the floor position and the stand height, and return the model to the marked points after each rest so the pose stays comparable.

Portrait sequence: build skull and jaw before features; eye sockets as recesses with lids as bands; nose as a triangular prism with planes; mouth on a cylinder, never a slot cut into a flat plane; ear as a spiral with a defined helix.

Moisture: mist and bag the clay overnight, keep the whole piece at even plasticity, and use slip for leather-hard additions so drying shrinkage stays uniform.

Depth classification: bas-relief projects less than half the form's natural depth and relies on shading; high relief projects more than half and may be undercut; sunken (intaglio) relief carves below the ground plane and projects nothing.

Ground plane: prepare it flat and consistent, draw the design onto it first, and let the highest point of the relief fix the total depth budget for the panel.

Foreshortening: forms receding into depth are compressed and rotated toward the frontal view, because the spectator's eye is roughly level with the panel centre.

Depth cues: overlap first, then size and vertical placement - distant figures sit higher on the ground and slightly smaller, near figures lower and larger.

Avoid tangents: never let the contour of one figure exactly touch another's; overlapping edges merge visually and destroy the silhouette, so offset them.

Undercut with restraint: 45° or steeper back-slopes keep the projection structurally attached; excessive undercutting weakens the relief and thins the edge until it chips.

Grouping: use odd numbers with unequal intervals, place the dominant figure off-centre, vary head heights, and design the negative spaces as deliberate shapes rather than leftover gaps.

Building the panel: press clay on in thin layers from the centre outward to avoid trapped air, keep thickness even, and back large panels with plaster or a wooden cradle before lifting.

Waste mould: built over the clay original, usually without keys, and chipped away at release; it is destroyed and yields exactly one positive, so it suits clay originals that will not be kept.

Piece mould: divided by shims into sections with carved keys and register marks; parting agent (soft soap, shellac or oil) between sections; reusable for repeated plaster, wax or resin casts.

Mother mould: a rigid plaster, scaglietti or fibreglass jacket that holds flexible or multi-part inner sections in register while casting.

Casting sequence: clean and seal the mould, apply release, mix plaster at about 2:1, build up in thin slush layers with the first layer brushed to pick up detail, de-air, then allow full set (warm to the touch) before demoulding.

Reinforcement: burlap, hemp or chopped fibreglass strands in the backing layer stop large plaster casts from cracking as they dry.

Finishing: remove flash and seam lines with a rasp, scraper or riffler, then wet-and-dry paper; seal dry plaster with shellac or acrylic size before waxing or patinating.

Surface treatment: thin acrylic or pigment washes and wax build tone without burying form; thick opaque paint fills undercuts and kills modelling.

Mounting and display: pin with brass or steel rod and epoxy into a drilled base, ensure the centre of gravity falls inside the base footprint, felt the underside, and light at 30–45° to reveal planes.

Proportion: the ratio of parts to whole and to each other; check head-units in figures, and use the golden section (1:1.618) when relating base, mass and total height.

Scale: the relationship of the piece to the human body and to its site; photograph a maquette at human eye level to predict how the full-size work will read.

Balance: symmetrical balance reads formal, static and ritual; asymmetrical balance reads dynamic - visual weight grows with size, dark value, coarse texture and high placement.

Rhythm: repeated motifs, edges or planes with variation in size, direction or interval; continuous edges lead the eye around the mass, broken edges stop it.

Texture must be scaled to viewing distance: coarse texture disappears at 5 m and fine texture disappears at 50 cm, so contrast smooth against rough deliberately.

Mass and void: closed form versus opened form; the silhouette must read against backlight, and enclosed voids count as shapes that need composing.

Unity, variety, dominance: one dominant idea, subordinate supporting forms, small accents; equal emphasis everywhere produces clutter, not richness.

Judgement protocol: assess silhouette at 3 m, proportion and transition of planes at 1 m, surface finish at arm's length; a piece that fails any distance is not finished.

Portfolio spine: 8 to 12 finished works with four-view photographs each, plus preparatory sketches, at least two maquettes, material tests and a dated studio log.

Record sheet fields: title, date, dimensions (H × W × D in cm), medium, armature type, number of sittings or hours, photographic reference used, problems encountered and how they were solved.

Process evidence: dated photographs at armature, block-in, refinement and finishing stages; examiners mark documented process, not only final polish.

Viva structure: state the intention, describe material and process, name the strongest and weakest passage in the work, and cite one historical or folk work that informed the piece.

Terminology to use correctly: armature, block-in, relief, undercut, waste mould, piece mould, cire-perdue, patina, maquette, contrapposto, leather-hard.

Display for viva: plinths levelled at eye height, typed labels with title, medium, size and year, directional lighting at 30–45°, and the record book open at the matching page.

Record discipline: every entry signed and dated, no undated work, no work submitted without a photograph, and the log must match the pieces physically present.

Common deductions: unattributed copies presented as original work, mismatch between record and submitted pieces, missing safety notes on materials used and dust control.