How to practice drawing

Six guides to the fundamentals, written beside the code that scores them.

This site has 43 drills on it. Each one gives you a mark out of 100 and then gets out of the way, which is fine for a warm-up and useless as teaching. These six guides are the other half: what the drill is actually measuring, why that is the thing worth measuring, and what to change tomorrow when the number comes back low.

They are written by the person who wrote the scoring, and that is the only thing they can offer that a book cannot. When an article says a line is too curved or a value is a bit off, you have to take its word for it. Here there is a function that decided, and it can be quoted. Every threshold in these guides — every tolerance, every cut-off, every point value — is read out of the drill's own js/game.js before it is printed. Where a number cannot be traced to code, it is not in the guide.

Nothing here is scored by a model. The drills are closed-form geometry and colour arithmetic; four of them (Shade a Sphere, Crop It, Focal Placement and Gesture Capture, each marked curated in the corner of its card) compare you against a hand-written answer key instead, because taste has no formula and pretending otherwise would be a lie told in decimal places.

the six chapters

6 guides · 43 drills

read one, then go and do the drills it names — the guide is the half that says why

What is in each chapter

Colour: what you see against what is there

The colour chapter covers mixing by eye, the difference between a hue error and a chroma error, warm and cool as a relationship rather than a list, and why a shadow on a sunny day is blue. Its measuring stick is CIE Lab: Color Mixer gives a full 100 to any match within ΔE 2 — the CIE76 just-noticeable difference, the point where two colours side by side stop being distinguishable — and then falls off linearly to zero at a window that widens with the target's own chroma, clamped between 16 and 50 ΔE. That widening is a teaching decision, not a technicality: a near-grey is genuinely harder to read than a vivid orange, and the scoring says so out loud. The first item of every round is graded against a window 1.35 times as wide as the rest, for the same reason — it is the first number a beginner ever sees.

Value & light: what survives when the colour is turned off

The value chapter is the one most likely to change a drawing this week, because value is what a photograph keeps in greyscale and what a painting is built out of. It covers reading lightness with the colour argued away, the anatomy of a shaded sphere, three-value thumbnails, and building a gradient with your own hand. Value Squint scores a match as 100 × (1 − ΔL*/22) with the first 1 L* forgiven for slider granularity — so it takes a miss of 23 L*, a little over a fifth of the whole black-to-white scale, to score nothing at all. That is how coarse value judgement is allowed to be and still be worth something.

Line & hand: the mark, before the drawing

The line chapter is about pulling from the shoulder, committing instead of steering, and why drawing the same line four times is a real exercise rather than a punishment. Steady Lines measures the RMS perpendicular drift of your stroke away from the straight path between the two dots. Anything under max(0.4% × |AB|, 3px) is a clean 100; the score runs out at ease × max(5.5% × |AB|, 16px). On a 300px pull that is a full 100 up to 3px of average wobble, and a zero at 16.5px with a pen or 33px with a mouse — a much wider door than most people assume they are missing.

Perspective: one fact, and everything built on it

The perspective chapter builds everything out of a single fact: parallel edges running away from you meet at one point, and that point sits at your eye level. Boxes, cylinders and cast shadows all stand on that. Vanishing Act scores a receding edge half on angle, against an 18° base tolerance, and half on how near your line passes the point, measured perpendicular to your own stroke and zeroing at 11% of the canvas width with a 42px floor. Both halves are then scaled by straightness, so a line corrected halfway across loses to one committed pull that was slightly wrong.

Composition: defaults you learn in order to break

The composition chapter is the one with no formula, and it is honest about that. It covers the thirds, lead room, the horizon, and why balance is about leverage rather than symmetry. Crop It awards 40 of its 100 points on subject placement, measured from the subject's visual centre to the nearest thirds crossing and normalised by the crop's diagonal: full marks inside 0.10, nothing left by 0.23. Dead centre lands at exactly one sixth of the diagonal, 0.167, which scores 19 of the 40 — the drill's way of saying that centring is not wrong, it is just the weakest of the strong options.

Observation: the seeing, not the hand

The observation chapter covers judging proportion, drawing the gap instead of the object, and holding a shape in memory long enough to put it down. Proportion Eye asks you to mark a half or a third by eye and calls a tick perfect if it lands within 1% of the measured length, with the score reaching zero 10% of the length beyond that. Both bounds have pixel floors — 3px and 20px before hardware easing — so a phone is never asked a harder question than a laptop for the same task.

What a score out of 100 can and cannot tell you

Every drill returns one number and it is easy to read too much into it. Three things are worth knowing before you do.

The number is compared with your own past rounds and nothing else. There is no leaderboard behind it and no cohort average it is quietly ranking you against. A 62 is a 62 against last Tuesday's 55.

It is tuned to what you are drawing with. Every motor-skill tolerance on the site is multiplied by an ease factor before it is applied: 1.0 for a pen or stylus, 1.5 for a finger, 2.0 for a mouse or trackpad. A mouse is allowed exactly twice the wobble of a pen tablet for the same score, because a wrist pivot cannot creep the way a nib can. The consequence is the part people miss — a best set on a pen tablet and a best set on a trackpad are two different measurements. Each drill prints the hardware it is scoring for; if you switch, expect your old best to be under a different-sized allowance.

A high score is evidence about one narrow thing. Landing 95 on Steady Lines says your strokes do not bow. It says nothing about whether you can decide where a line should go, which is a different and harder skill and is what most of the guides are actually about.

Where to start

If you want the reasoning first, read the chapter for whatever is currently going wrong in your drawings. If you would rather warm up and read later, three drills need no drawing hardware at all and take about two minutes each: Value Trap, Color Mixer and Steady Lines. A trackpad is enough for all three.

The habit that these guides assume is small and daily: one drill, two to four minutes, then close the tab. The chapters are there for the day the score stops moving, which is the day it stops being a warm-up and starts being a question.

All the drills: the catalogue, 43 of them · Free to use, no ads, no account needed · Scored by geometry and colour arithmetic, not by a model