Chalk art from the classroom to the street

Chalk has had at least three distinct lives: as a writing technology, as an artistic medium, and as a street performance. They share a material and almost nothing else, and each one made a virtue of a different property of it.

The slate and the school board

Before the classroom blackboard there was the individual slate: a small piece of stone in a wooden frame that each pupil wrote on and wiped clean. Its appeal was economic. Paper was expensive enough that giving every child a reusable writing surface was a serious saving, and a slate could be used indefinitely.

The individual slate has one structural limitation that shaped everything that followed: nobody can see it but the person holding it.

The large wall-mounted board solved that, and in doing so it changed what a classroom was. It made teaching a one-to-many performance. A worked example could be built up in front of everyone, step by step, with the earlier steps still visible while the later ones were written. Nineteenth-century teaching practice reorganised itself around this — rows of desks facing a single surface at the front — and it is worth saying plainly that the blackboard was an educational technology, arguably a more consequential one than most things since.

What it is unusually good at is thinking out loud. Mathematics and other derivational subjects still lean on boards for a reason that survives every attempt to replace them: a board is slow enough to follow, large enough to hold a whole argument at once, and easy enough to amend mid-thought. Slides go forward. Boards accumulate.

The board as artwork

Once the blackboard was a fixture of teaching, artists could use it as a readymade — a surface that already means "explanation in progress".

The best-known case is Joseph Beuys, who used blackboards extensively in connection with his lectures, discussions and public actions. He would draw and write on boards while talking, and the boards themselves were kept and exhibited as works. That is an odd object: a record of an argument, in a medium designed to be erased, preserved precisely because it was not. Beuys's boards carry diagrams, single words, arrows and the appearance of a mind being worked out in public — the thing a blackboard signals better than any other surface.

Blackboard drawing has continued to appeal to artists for that reason. The medium is legible as provisional, and that is hard to fake in paint.

The street: madonnari and pavement painting

The Italian tradition of street painting is associated with the term madonnari — a name connected to the religious subjects, particularly images of the Madonna, that itinerant artists reproduced on pavements and piazzas, working for whatever passers-by gave them. It is an old tradition, it was by no means a prestigious one, and it declined considerably before being revived in the modern era as an organised festival form, with events at which artists are invited to work on assigned sections of pavement over a day or several days while the public watches.

Dates, individual names and the details of particular festivals vary between accounts and are not repeated here where they cannot be stated with confidence. The shape of the story — an old itinerant devotional practice, a decline, and a modern festival revival that turned it into a public spectacle — is uncontroversial.

Two features of street work follow from the setting. It is done from above, often on hands and knees, which is physically demanding and gives a distorted view of your own drawing while you make it. And it is done in front of an audience for the entire time, so the process is part of the work in a way it never is in a studio.

Pastel, not really chalk

Serious street painting is usually done with soft pastels rather than with blackboard chalk. The reason is pigment. Blackboard chalk is a pale, low-pigment material designed to be visible on a dark surface and to be wiped off easily. Soft pastel is largely pigment with just enough binder to hold it in a stick, so it lays down saturated colour on grey stone and can be blended and layered. Street artists work in bright, dense colour, which blackboard chalk cannot supply — the tradition is called chalk art, but the material mostly is not chalk.

Anamorphic pavement drawing

The modern form most people have seen is the "3D" pavement drawing, where a hole seems to open in the ground or an object appears to stand up off it. The technique is anamorphosis, which is much older than street art and has a long history in painting and architectural decoration.

The principle is a single viewpoint. The image is drawn so distorted across the ground that it is unrecognisable to anyone standing anywhere else, and resolves into a coherent scene only from one specific position — usually a marked spot at a particular height, which is why these works are always accompanied by a designated place to stand, and often a marked place to put a camera.

Setting one up means projecting a picture that would look correct from that viewpoint onto the ground plane, which stretches enormously as it recedes. Objects meant to appear near the viewer occupy a small area, and objects meant to appear far away are drawn hugely elongated. Practitioners have used grids, optical projection and, more recently, digital previews to work out the distortion, then transfer it to the pavement. The consequence for a spectator is that the drawing looks like a mess from every angle except the one it was designed for, and the photograph taken from that mark is where the illusion actually lives.

Impermanence as the point

Every kind of chalk work is temporary. Rain takes the pavement piece, feet take it faster, the lesson is wiped at the end of the hour, and the board is reset for the next class. Practitioners talk about this constantly, and mostly not as a loss.

A few reasons recur. Nothing is precious, so there is no reason to be timid — you can make a large, ambitious, obviously imperfect thing and lose nothing but a day. The audience is watching an event rather than viewing an object, and knowing it will be gone is what makes them stop and watch. And the artist is freed from the whole apparatus of preservation, sale and storage that surrounds permanent work.

The same logic operates at a much smaller scale in a classroom. Wiping the board is not a failure of the lesson; it is what makes the board usable tomorrow.

The photograph as the surviving artefact

Which raises the awkward modern question. If the work is gone, what circulates is the photograph, and for anamorphic pavement drawing the photograph is more than documentation — the illusion only exists from one viewpoint, and the camera stands at that viewpoint. The photograph is not a record of the artwork; in a real sense it is the artwork's only correct view.

Something similar happened to Beuys's boards. Keeping an erasable surface is already a decision to interrupt the medium's natural end, and the kept board is not quite the thing that existed during the lecture. Chalk work therefore has an unusually complicated relationship with its own documentation, and the honest version is that the record and the event are different objects.

Doing it now

All three traditions are still practised. Boards remain in classrooms and lecture theatres, hand-lettered chalkboards are a fixture outside cafés, and street painting festivals continue. The pavement version has the highest barrier — a large permitted surface, hours on your knees, and weather.

A tablet is not a substitute for any of that, and pretending otherwise would be silly. It is a reasonable place to practise, plan and try things that would be expensive to attempt on stone: lettering drills, thumbnail layouts for a real board, working out how a piece is built up stroke by stroke. Flying Chalk keeps the part that matters for practice — a real surface with tooth, dry skip when you move fast, and a wipe that is animated as actual eraser strokes rather than a fade, because the wipe is part of the medium. What it cannot give you is the crowd, the weather, or the knowledge that tomorrow it will be gone.

Related guides

• Why chalk marks look the way they do
• How children's drawing develops, and what the stages don't tell you
• Why digital chalk and pastel look different from a brush