/ˈskwɛər.ɪŋ ˈʌp/

Squaring up

noun · drawing method

What it is

To square up a picture, the artist rules a grid of equal squares over the reference (often on a transparent overlay so the original is unmarked), then rules a second grid of squares over the working surface. The two grids have the same number of rows and columns, but the squares on the surface can be larger. Each square on the surface then corresponds to exactly one square on the reference, and the artist copies the lines cell by cell — a small, contained drawing problem repeated across the whole image. Because the ratio between the two grids is constant, the copy comes out at a predictable enlargement or reduction of the original.

Squaring up is the traditional studio term for what many artists now simply call the grid method. It differs from freehand copying in that proportion is handled by the geometry of the grid rather than by eye, which is why it has long been the standard way to scale a study up to a mural or a large canvas.

Etymology

The phrase describes the act literally — laying squares over an image — and the technique long predates the name. Its most-cited ancestor is the drawing frame described by Leon Battista Alberti in On Painting (1435), the gridded "veil" a painter looked through to plot a scene onto a matching grid on the panel.¹ By the Renaissance the practice of ruling squares to transfer and enlarge a design was widespread in workshops, and "squaring up" became the ordinary English studio term for it.

Examples in use

A muralist squares up a small colour study so it can be transferred, cell by cell, to a wall many times its size. A student squares up a photograph to practise judging proportion within each cell before attempting the same subject freehand. A copyist squares up an old master reproduction to reproduce it at the original dimensions. Grid Maker Pro's free web tool draws the transfer grid over a reference for you at any division, so no ruling by hand is needed — see how to enlarge a drawing.