Castilla-La Mancha PAU Técnicas de Expresión Gráfico-Plástica: Graphic-plastic expression: materials, image-making and project evidence

Materials, tools and techniques: properties, handling and care

This independent subject chapter develops Materials, tools and techniques: properties, handling and care. The following examples explain concepts and explicit classroom models, rather than a current regional paper, official mark allocation or certified production procedure.

Supports and grounds

Grammage (gsm) is weight, not quality: thin paper is more prone to cockling under a wash; even heavy cotton paper can buckle depending on sizing, moisture and mounting.
Sizing (for example, gelatin or suitable synthetic agents) controls absorbency; unsized paper feathers ink and bleeds.
Acid-free, buffered papers and boards resist yellowing; wood-pulp board embrittles and browns.
Grounds: acrylic gesso for canvas and panel, traditional glue-and-chalk for tempera panels; a toned ground helps you judge values while painting.

Pigments, binders and diluents

Paint is pigment plus binder: gum arabic (watercolour, gouache), egg yolk (tempera), linseed oil (oil), acrylic polymer dispersion (acrylic), wax (encaustic, oil pastel).
Pigments differ in opacity, tinting strength, lightfastness and toxicity: opacity and permanence depend on the specific pigment and formulation; some traditional pigments present significant hazards. Select suitable classroom materials from their documented properties.
Diluents: water for water-based media, a compatible manufacturer-specified medium for oil, subject to the studio safety arrangements. Thin acrylic with medium rather than excess water, or the polymer film loses integrity.

Tools: selection and care

Kolinsky or sable keeps a point and spring for watercolour; hog bristle is stiff enough for oil impasto; squirrel holds a soft wash; synthetics suit acrylic and sharp edges.
Shapes carry function: round for line, flat for blocks, filbert for rounded blending, fan for texture, mop for washes.
Clean acrylic out before it cures, because a dry polymer film no longer re-wets; clean and dry brushes as appropriate to their materials before storage; store markers according to their particular manufacturer instructions; use a kneaded eraser on graphite and never scrub charcoal.

Worked example

A three-hour still life with strong tonal contrast. A multi-layer oil process with intervening drying would not suit this short session, although wet-into-wet oil painting remains possible; watercolour struggles to restore clean highlights once the paper is stained. Gouache on 300 gsm cold-press board answers the brief: body colour is opaque enough to place a light shape over a dark one, some passages can be reactivated or adjusted, subject to their pigment and support, and the matt surface dries quickly. The reasoning is opacity, re-wettability and drying time, not personal preference.

Traps that cost marks

Assuming a heavy paper is automatically sized for wet media.
Spraying fixative in thick clouds, flattening charcoal and dulling pastel.
Thinning acrylic with too much water and calling the result a wash.
Leaving natural brushes standing bristle-down in water, which curls the hairs permanently.

Drawing techniques: dry media and wet media

This independent subject chapter develops Drawing techniques: dry media and wet media. The following examples explain concepts and explicit classroom models, rather than a current regional paper, official mark allocation or certified production procedure.

Dry media

Graphite runs on the H/B scale: 2 H for construction lines, HB for general work, 6 B for darks. A sharp point draws line, the side of the lead lays broad tone. Heavy pressure produces gloss that betrays overworking.
Charcoal: vine or willow charcoal has little binder, is pale grey, dusty and easily erased; compressed charcoal is dense black, harder to lift. A kneaded eraser lifts without abrasion. Any fixative use must follow the product instructions and the supervised studio ventilation arrangements.
Pastel: soft pastel is pigment-rich with minimal binder and needs paper tooth (Mi-Teintes, sanded card) to hold layers; hard pastel takes detail; oil pastel uses a wax/oil binder and remains substantially different from dry pastel; choose blending and removal methods compatible with its product and support. Fixative dulls the brightest passages.
Coloured pencil: wax-based pencils blend by burnishing or solvent and can bloom white; oil-based pencils hold a finer point. Work light to dark and keep the lightest values as bare paper.

Wet media

Ink is either waterproof or water-soluble; check before layering. A dip nib hatches, a brush carries wash, a technical pen gives an even line.
Wash is ink diluted with water. Build it in successive layers from light to dark and let each dry, or you lift the layer beneath and produce a muddy bloom.
Markers: alcohol-based markers blend and layer but bleed through thin paper, so use marker paper; water-based markers can show streaking or reactivate depending on the paper and formulation. Working from light to dark is a useful starting strategy, but reactivation and lifting vary by product and paper.

Worked example

A four-value ink study of a sphere: dilute ink to roughly 10%, 25%, 50% and 80%; reserve paper white for the highlight; lay the 10% wash over the whole form; add the 25% band up to the terminator; place the 50% in the core shadow; keep the 80% for the cast shadow edge and a few hatched accents with a 0.3 pen. Each layer dries before the next, so no wash disturbs the one below.

Traps that cost marks

Changing hatching direction mid-area, which reads as a change of plane.
Spraying fixative on ink or watercolour, which does nothing useful and can bloom.
Drawing water-based marker over non-waterproof ink and smearing the linework.
Building charcoal darks by rubbing instead of layering, which kills the paper tooth.

Painting techniques: watercolour, gouache, acrylic and oil; supports and mixed media

This independent subject chapter develops Painting techniques: watercolour, gouache, acrylic and oil; supports and mixed media. The following examples explain concepts and explicit classroom models, rather than a current regional paper, official mark allocation or certified production procedure.

Watercolour and gouache

Watercolour is transparent: white is reserved paper, not paint. Wet-on-wet gives soft edges, wet-on-dry crisp ones, dry brush gives broken texture. Lifting, masking fluid and salt extend control. Values dry lighter than they look wet, so paint slightly stronger than intended, and uneven drying produces blooms.
Gouache is an opaque water-based paint, with opacity coming from pigment loading and formulation rather than necessarily added white or chalk: matte, re-wettable and capable of light-over-dark. Thinned gouache behaves like watercolour and lifts easily, so keep opaque passages fairly dry.

Acrylic and oil

Acrylic is a polymer emulsion: it dries fast, forms a water-resistant film when cured and cannot be re-wetted. Mediums control gloss, transparency, texture and open time. Adhesion depends on a suitable clean support, preparation and compatible products.
Oil dries slowly by oxidation, allowing blending and reworking. Follow fat over lean: later layers must be compatible with the earlier layers in flexibility and drying behavior; this is not a guarantee against every cause of cracking. Glazes go over dried opaque passages; impasto uses stiff paint and a knife.

Supports, preparation and mixed media

Stretch canvas or use rigid panel, prime with gesso, and sand between coats for a smooth surface. Acrylic may be used under oil once fully cured; oil under acrylic is unsafe because the acrylic cannot key to the oily film.
Mixed media succeeds when you respect drying order and adhesion: water-based layers first, oil-based last, and test collage adhesives for staining.

Worked example

A portrait with a strong shadow side. Choose oil: an compatible lean underpainting and earth colours establishes drawing and value; opaque mid-tones go on once it is touch-dry; the darks are glazed thinly with more oil; final highlights are impasto. The layer structure is planned for compatibility rather than treated as a guarantee against cracking, and the slow drying lets you rework edges across sessions.

Traps that cost marks

Inverting fat over lean and blaming the canvas when the paint cracks.
Painting acrylic over an oily or waxy surface and watching it bead.
Using white watercolour for highlights and losing the paper's luminosity.
Over-thinning acrylic with water until the binder fails and the film dusts off.

Graphic design and illustration: composition, typography, layout and visual communication

This independent subject chapter develops Graphic design and illustration: composition, typography, layout and visual communication. The following examples explain concepts and explicit classroom models, rather than a current regional paper, official mark allocation or certified production procedure.

Composition and hierarchy

Establish a single dominant focal point, then order the rest by contrast, scale, weight and position. White space is an active element, not leftover paper.
Alignment and proximity group related items; repetition creates rhythm; contrast of size or value separates levels.
Structures such as thirds, columns and proportional divisions can organize alternatives. Actual reading paths depend on language, content and audience; test the intended hierarchy rather than assuming a universal Z or F path.

Typography

Anatomy: x-height, ascender, descender, counter, stem, serif. x-height governs apparent size at a given point size.
Classify families as serif, sans serif, slab, script and display, and note humanist, transitional and modern serifs.
Spacing terms are examined precisely: kerning adjusts a single pair, tracking adjusts a range of characters, leading is line spacing, measure is line length, comfortable at roughly 45 to 75 characters.
Legibility concerns individual characters; readability concerns whole passages. Both collapse when the measure is too long or leading too tight.
Build hierarchy with size, weight, case, colour and position. Three typefaces is already a lot.

Layout and visual communication

Grid systems use columns, gutters, margins, modules and a baseline grid; breaking the grid only works once the grid is established.
Illustration: thumbnails, roughs and comprehensives move from idea to resolved image; line weight and consistent style carry the message.
Semiotics: an icon resembles its object, an index points to it causally, a symbol relies on convention. Contrast for accessibility means value contrast, not hue alone.

Worked example

An A 2 concert poster. The artist name is set largest in a condensed sans at about 120 pt; the event date sits at half that size in the same family, bold; the venue and ticket line use a secondary text style selected for the actual viewing distance, ranged left on a two-column grid. One image occupies the top third, the type stacks down the left column, and a single high-contrast colour marks the date. Hierarchy explains the sequence: name, date, place, detail.

Traps that cost marks

Confusing kerning with tracking.
Too many typefaces competing in one layout.
Text in low value contrast against its background.
Centring every element so nothing dominates.
Setting body copy in a script or display face.

Printmaking and reproduction: relief, intaglio, planographic and stencil

This independent subject chapter develops Printmaking and reproduction: relief, intaglio, planographic and stencil. The following examples explain concepts and explicit classroom models, rather than a current regional paper, official mark allocation or certified production procedure.

Relief

Linocut and woodcut carry ink on the raised surface; what you cut away stays paper-white. Gouges: U-shaped for rounded removal, V-shaped for fine lines.
The printed image is mirrored, so lettering must be reversed on the block.
Reduction cuts destroy the block progressively; you print the lightest colour first, carve away, then print darker over the same sheet.
Registration marks keep successive colours aligned; a baren or press provides pressure; oil-based inks stay open longer than water-based ones.

Intaglio

Ink sits in incised lines while the plate surface is wiped clean; damp paper and high pressure pull it out, leaving a plate mark.
Etching uses a resistant ground and a controlled mordant process; this identifies the process, rather than supplying chemical operating instructions; drypoint raises a burr that gives a velvety, short-lived line; engraving cuts with a burin; aquatint uses a granular resist to create tonal areas; mezzotint rocks the plate and works from dark to light.

Planographic and stencil

Lithography relies on grease and water repelling: crayon or tusche on stone or aluminium plate. Monotype gives one unique pull; offset transfers the image via a rubber blanket for mass reproduction.
Screenprint forces ink through a mesh with a squeegee; higher mesh counts hold finer detail, lower counts deposit more ink. Photo-emulsion stencils allow photographic imagery; hand-cut stencils and pochoir work directly with a brush.

Editioning conventions

Pencil below the image: edition number bottom left, title centre, signature and date right. AP marks an artist's proof; trial proofs precede the edition; cancelled plates prevent further pulls.

Worked example

A two-colour reduction linocut, edition of twelve. Print twelve sheets in the lighter colour, registering with a jig. Carve away everything that must remain that light colour. Print the darker colour across the same sheets. Number 1/12 to 12/12 in pencil. The planned numbered edition contains twelve finished prints. Additional proofs may exist; destroying the earlier block state does not by itself prove the number of impressions made.

Traps that cost marks

Forgetting reversal in direct relief or intaglio printing, or assuming screen and stencil transfer always reverse the image in the same way.
Over-inking an intaglio plate and losing the finest lines.
Printing intaglio on dry paper, which blocks ink transfer.
Choosing too coarse a screen mesh for delicate detail.

Image analysis and visual language: formal elements, colour, texture, composition and meaning

This independent subject chapter develops Image analysis and visual language: formal elements, colour, texture, composition and meaning. The following examples explain concepts and explicit classroom models, rather than a current regional paper, official mark allocation or certified production procedure.

Formal elements

Point, line, shape, form, value, colour, texture and space. Describe line by direction, weight and continuity, shape as organic or geometric, form as modelled volume.
Space is built by overlapping, scale, placement, linear perspective and atmospheric perspective, and by figure-ground relationships.

Colour

Three coordinates: hue, value, saturation. Hue is the family name, value its lightness, saturation its purity.
Paint mixes subtractively; screens mix additively. Primary, secondary and tertiary relationships differ accordingly.
Contrasts worth naming: complementary, simultaneous contrast, warm-cool, light-dark, saturation contrast, quantity contrast.
Harmonies: analogous, complementary, split-complementary, triadic, monochromatic. Local colour is the object's perceived colour; optical mixing builds colour in the eye, as in pointillism.
Value carries legibility and structure more strongly than hue, so identify the value pattern before discussing colour mood.

Composition

Balance may be symmetrical, asymmetrical or radial; rhythm comes from repetition and interval; proportion and scale organise relative size; the focal point is placed by contrast, isolation or convergence of leading lines; negative space is a shape in its own right.

Meaning

Separate denotation, what is shown, from connotation, what it suggests. Classify signs as icon, index or symbol. Read iconography, then context: commission, audience, intended location and medium all constrain meaning.

Worked example

A war recruitment poster. The value pattern is near-black against cream, so the figure dominates; the red accent is the only saturated hue and marks the enemy. The viewpoint is low, making the soldier monumental; the diagonal rifle leads the eye to the headline in heavy sans capitals. Denotation is a soldier and a slogan; connotation is duty and threat. Each formal choice supports the call to action, which is the interpretive step examiners credit.

Traps that cost marks

Describing what is in the image without analysing how it works.
Writing 'strong colour contrast' when the actual contrast is value or saturation.
Confusing texture, which is surface quality, with pattern, which is repeated motif.
Treating value as a by-product of hue rather than an independent coordinate.

Creative process and project development: planning, experimentation, documentation and presentation

This independent subject chapter develops Creative process and project development: planning, experimentation, documentation and presentation. The following examples explain concepts and explicit classroom models, rather than a current regional paper, official mark allocation or certified production procedure.

Brief and constraints

Restate the brief in one sentence: purpose, audience, format, deadline, budget, materials available. Turn it into three or four testable success criteria you can check at the end.

Research and references

Distinguish primary sources (your own observation, tests, photographs) from secondary ones (books, exhibitions, websites).
A moodboard organises references by colour, texture, composition and technique, and every item is annotated with what you intend to take from it.

Experimentation

Thumbnails test composition cheaply; colour studies test palette; material samples and test prints test technique.
Change one variable at a time so you can attribute the result. Record failures with the reason, because examiners credit informed rejection of an approach.

Documentation

A dossier or sketchbook should be dated and annotated with technical data: medium, support, dimensions, working time, drying problems.
Photograph stages, not only outcomes, and write short reflective notes on what changed and why.

Planning

A simple timeline with milestones beats an elaborate chart. Identify risks specific to the technique, such as oil drying time, print registration, scanner resolution or adhesive staining, and state a contingency for each.

Presentation

Mount with a clean window mat, label each work with title, medium and dimensions, and order a portfolio so it opens and closes strongly. Digital files need consistent resolution and colour mode, and the verbal defence should summarise intention, process and evaluation in about a minute.

Worked example

A six-week mixed-media illustration. Week 1: brief analysis and reference board. Week 2: fifteen thumbnails, three shortlisted. Week 3: material tests combining acrylic, collage and coloured pencil, documented with samples. Week 4: resolved drawing at full size. Week 5: final piece with stage photographs. Week 6: mounting, labelling and a written evaluation against the criteria. Each week produces evidence, which is what the mark scheme rewards.

Traps that cost marks

Showing only the final piece with no route to it.
An undated, unannotated sketchbook that reads as decoration.
Changing direction silently instead of explaining the reason.
Ignoring the brief's format or deadline constraints in the evaluation.