Drawing for a clean reading

Any order#

Draw in whatever order suits you. The reader looks at the finished drawing, not at the order of its strokes: draw every box first and the arrows after, start from the middle, or come back later to add a head or a missing shape. On 300 of Didi's drawings, each read in five shuffled orders, 298 read the same every time, and the other two differed only in which stray mark joined a line. One thing does follow the drawing: a line with no head points the way it was drawn.

Shapes#

• Close your shapes. End each outline near where it began. A small overshoot is fine; a wide gap reads as a line.
• Leave a little room between shapes, so each line has length of its own.
• Draw groups last and roomy, around the shapes they hold, with clear space inside the edge.

Lines and heads#

• Start and end lines near the shapes, or point them straight at them. A line's end counts as touching a shape when it stops inside it, or short of it by up to about a third of the shape's longer side (at least 18 drawing units, at most 44). Farther off, it still reaches a shape it points straight at.
• Curved lines are fine. An arc or an S between two shapes reads as an arrow like a straight line does; Mermaid draws its own lines in the diagram.
• Arrowheads may be as big as a short line. Between shapes drawn close together, a short line with a big head reads as an arrow, not as a small diamond.
• Heads of any common kind work. A hook at the tip, a filled-in head before or after the line, a separate "V", or a small closed triangle all work; How people draw arrows shows a filled-in head, a separate head, and a closed triangle. A head with barbs longer than half its line can be read as a line itself.
• Draw a shape and its line in one go if you like. A box and the line that leaves it, or a line and the box it leads to, can be one stroke. The line must run well clear of the box. The eraser then takes both, and its second kind, which erases only what it passes over, takes just the part you sweep over. How people draw arrows shows one.
• Leave clear gaps between dashes, and keep each dash short: up to about 40 drawing units, with gaps about as long as the dashes. Very short dabs are too small to read. A plain line drawn in short pieces with gaps between them reads as dotted; its menu under Names sets it back to plain.
• Go over a line close to it for a thick one, from either end. A second line drawn more than about 10 drawing units from the first is a second arrow.

Zoom and checking#

• Zoom out for room. The drawing zooms from 10% to 400%. Draw at whatever size feels natural on screen: the reader reads each drawing at the size it was drawn. Where you can, draw a drawing at one zoom, since it is read at the zoom most of its strokes were drawn at.
• Look at the shading. Marks the reader left out are shaded on the drawing. Erase them, redraw them, or leave them: they do not change the code.