Diagnose / Oil
Oil mistakes
Slow drying; oxidises and cures over weeks. Fat over lean: lean paint first, richer paint later.
24 faults, most common first
- All edges equally hard, no lost-and-found edgesEvery object, figure, and shadow contour has a sharp, razor-crisp boundary. Rescue
- Bottles and vases lopsided: no centre axisA symmetrical object has mismatched left and right contours. Rescue
- Cast shadows painted black and opaqueThe shadows cast by objects appear dead, opaque, and jet-black. Rescue
- Copying every detail of a reference without simplifyingThe drawing is filled with high-contrast, tiny marks spread uniformly across every square centimetre. Rescue
- Muddy mixes from too many colours on the paletteColours across the canvas look lifeless, murky, and homogenised. Rescue
- Not checking work in a mirror or at a distanceA portrait or figure exhibits an unintended tilt, an eye sitting higher than its partner, or an overall drift to one side. Rescue
- Overworking wet paint into mudPaint layers have blended into a cloudy, indistinct paste. Rescue
- Subject has no focal pointThe canvas contains equal amounts of detail, contrast, and sharp edges everywhere. Rescue
- Colour palette fights: unplanned mix of many chromasThe painting features high-intensity, pure pigment across every corner without a clear dominant hue. Rescue
- Composition cut off at awkward placesLimbs, joints, or primary objects hit the boundary of the page in an awkward manner. Partly
- Distance not shifting cooler and lighterThe background landscape elements appear too close, harsh, and loud. Rescue
- Local colour only: ignoring reflected light and temperatureThe object is painted using only its local hue mixed with black for shadow and white for highlight. Rescue
- Skin in the lights overpainted whiteLight areas of the skin are painted with pure or nearly pure titanium white. Rescue
- Skin looks dead: no colour variation in the shadowsThe shadow areas on the face resemble cold grey clay rather than living tissue. Rescue
- Stopping too early because it looks fine in the phone photoThe physical artwork appears faint, lacking rich darks and crisp details, despite reading clearly when photographed. Rescue
- Sunk-in patches: dull spots where oil sinks into the groundCertain areas of the finished painting look flat, dry, and sunken, while neighboring patches retain a rich, lustrous shine. Rescue
- Tangents: edges kissing awkwardlyTwo distinct edges in the picture touch exactly at their borders without clear overlap. Rescue
- Thick paint too early making corrections impossibleHeavy ridges and sticky piles of impasto paint block further brushwork early in the painting. Rescue
- Too much medium: slippery, weak paintThe paint feels overly slick, greasy, and uncontrollable on the canvas. Rescue
- Fat over lean violation leading to cracksFine cracks, alligatoring, or crawling wrinkles appear across upper paint layers. Partly
- Framing wrongly: cropped or overmattedThe outer border of the frame or mat cuts directly into the subject matter, leaving no margin for the composition to breathe. Rescue
- Painting on unprimed or absorbent canvasThe brush drags awkwardly across the canvas as if all liquid is being instantly drained. Start again
- Shapes all similar in sizeThe masses, light patches, or negative spaces across the work are all roughly the same dimensions. Rescue
- Varnishing too soon causes cloudinessA cloudy, milky haze covers portions of the varnished painting. Partly
Faults that apply to every medium are collected on the any medium page. Measuring problems may also be worth checking with the proportion grid, and paint drying questions with the drying time guide.
Checklist: check your work against these
Each line is the quick test from the matching page. Print this page for a studio checklist.
- All edges equally hard, no lost-and-found edges. Squint at your subject: do you actually see every edge with equal sharpness, or do certain contours dissolve into the background values?
- Bottles and vases lopsided: no centre axis. Hold your drawing vertically in front of a mirror or invert the sheet upside down; the asymmetry will jump out instantly.
- Cast shadows painted black and opaque. Place a scrap of pure black paper next to your cast shadow: is your painted shadow identical to the black paper with zero transparency or colour temperature?
- Copying every detail of a reference without simplifying. Squint heavily at your source photo; if half the tiny details disappear in your blur, but they are clearly rendered on your paper, you have over-copied.
- Muddy mixes from too many colours on the palette. Check your palette: count the separate blobs of paint you dragged into your main working puddle. If there are more than three, you are over-mixing.
- Not checking work in a mirror or at a distance. Hold the work up to a flat mirror or invert the canvas upside down right now; any lean will jump out immediately.
- Overworking wet paint into mud. Drag a dry brush gently over the area: if it immediately lifts off a grey sludge instead of blending an edge, the layer is physically exhausted.
- Subject has no focal point. Look away for five seconds, then glance quickly at your artwork: if your eyes dart around frantically rather than settling on one clear spot, you have no focal point.
- Colour palette fights: unplanned mix of many chromas. Take a photo of your painting and desaturate it halfway; if the composition suddenly becomes calmer and easier to read, your saturation is unmanaged.
- Composition cut off at awkward places. Hold your hands or two sheets of paper over the margins to test shifting the crop inward or outward by two centimetres.
- Distance not shifting cooler and lighter. Sample the colour of the distant ridge and place a dab of it next to your foreground elements: if the distant mix has strong warm yellows or dark values, it lacks aerial perspective.
- Local colour only: ignoring reflected light and temperature. Examine the shadow edge of the object; if it is merely a darker, duller version of the light side, you have missed ambient bounce.
- Skin in the lights overpainted white. Take a photo of your painting, zoom into the brightest highlight, and compare it against the white of your palette paper.
- Skin looks dead: no colour variation in the shadows. Take a colour picker or squint closely at the shadow side of your portrait: is it merely a desaturated dark grey version of the lit side?
- Stopping too early because it looks fine in the phone photo. Step back three metres from the easel in normal room light without your device and see if the darkest darks still hold authority.
- Sunk-in patches: dull spots where oil sinks into the ground. Look across the painting against an angled light: if the surface sheen switches erratically between glossy and matte patches, you have sunken-in passages.
- Tangents: edges kissing awkwardly. Trace the silhouette outlines with your finger to spot any places where two different objects share an identical boundary line.
- Thick paint too early making corrections impossible. Rest your finger lightly near the problem area: if deep wet ridges squish under light touch while your overall structure is still unfinished, you applied impasto too early.
- Too much medium: slippery, weak paint. Dip a brush into your mix and touch the canvas; if paint pools instantly around the stroke edges leaving a transparent center, you have drowned the pigment.
- Fat over lean violation leading to cracks. Review your medium mixtures: did you use pure solvent over paint containing heavy oil medium or straight tube black?
- Framing wrongly: cropped or overmatted. Place four scraps of white paper along the edges of your painting to simulate a mount window and see if any focal points get crowded.
- Painting on unprimed or absorbent canvas. Place a tiny drop of water or mineral spirit on the bare canvas edge: if it absorbs instantly within five seconds, the ground is unprimed or far too absorbent.
- Shapes all similar in size. Squint at the artwork and group the elements into basic shapes to see if they all take up roughly equal area.
- Varnishing too soon causes cloudiness. Press a thumbnail firmly into the thickest paint area on an unvarnished edge: if it leaves a mark or yields, the paint was far too soft for final varnish.