Diagnose / Causes / Materials
Materials mistakes
Paper, paint, tools and how they behave.
- Early layers pressed too hard leaving no toothPastel. The paper surface has become slick, shiny, and greasy-looking, refusing to accept any fresh pastel layers. Partly
- Muddy greys from overworking and over-blendingCharcoal. The entire drawing sits in a middle-grey fog. Rescue
- Paper buckles because it is thin or unstretchedWatercolour. The paper surface undulates with severe ripples. Rescue
- Brushes too small leading to fussy detailWatercolour. The painting is covered with tiny, distinct brush strokes instead of smooth, readable planes. Rescue
- Fixative darkening coloursPastel. Delicate highlights, aerial haze, and soft tints lose their luminosity. Partly
- Ink blobs and bleeding on the wrong paperInk. Clean line work is spreading outwards into fuzzy, feather-like fringes. Start again
- Paper tearing or burnished by over-erasingPencil. The surface of the paper has become rough, fuzzy, or torn, with visible paper fibers lifting off the sheet. Start again
- Paper too smooth and clogged with pigmentPastel. The paper surface appears slick and burnished, unable to hold further layers of pastel. Partly
- Plastic-looking, thick, skinned paint layersAcrylic. The paint surface has a slick, rubbery gloss and bulbous edges where paint was applied too heavily. Partly
- Shiny graphite sheen from heavy pressurePencil. The darkest areas of the drawing reflect light with a harsh, silvery, metallic sheen. Partly
- Streaky flat areas that should be uniformGouache. A flat wash shows uneven brush lines, light bands, and patchy density. Rescue
- Too much medium: slippery, weak paintOil. The paint feels overly slick, greasy, and uncontrollable on the canvas. Rescue
- Canvas texture coming through glazes unevenlyAcrylic. Glazes or thin fluid washes look speckled and uneven across the picture. Rescue
- Charcoal fixed too heavily and gone shinyCharcoal. The rich, velvety matte surface of the charcoal has turned unevenly shiny, dark, or plasticky. Partly
- Cracking when painted too thicklyGouache. Heavy impasto marks or thick layers develop hairline fissures and begin to chip away from the surface. Partly
- Painting on unprimed or absorbent canvasOil. The brush drags awkwardly across the canvas as if all liquid is being instantly drained. Start again
- Cracking or peeling from thick paint on a slick surfaceAcrylic. Heavy acrylic paint films are pulling away from the support or lifting at the corners. Partly
Other causes
- ObservationDrawing what you think exists instead of what you see.
- MeasuringProportion, angle and placement errors that checking would catch.
- Drying and timeWaiting, layer order and drying behaviour.
- CompositionHow shapes sit on the page.
- ColourMixing, temperature and saturation.
- EdgesHard, soft and lost edges.
- FinishingFinal stages, protection and presentation.