Art and Design

Measuring and Magnifying

How can you make a small sketch into a large painting, or paint a mural the size of a house? Artists had this problem for centuries. Their solution was to draw a grid.

You can find drawings with grids dating back to the Renaissance. Here is one by Graham Sutherland in the 1940s. He made sketches of thorn trees in Pembrokeshire and enlarged the ones he liked to make big paintings. You can see how he redrew the sketch accurately but changed the colour and some details. The painting is 127cm high. He made other versions too.

To enlarge the tiny drawing he covered it with horizontal, vertical and diagonal lines. He drew the same grid on a much bigger scale for his painting. He could copy the painting one square at a time without any mistakes or distortion. 

Ruth Jên Evans painted this 14m high mural at Talybont near Aberystwyth in 2006. She made a drawing and put a grid over it. She then stood on a scaffolding to copy each 0.6m square at a time.

Y Lolfa Mural, Talybont, Aberystwyth


You will need drawing paper, tracing paper, pencils and rulers.

You are going to make a large drawing of a small image you like.

  1. Choose a small image, for example a sketch, a cartoon, or a postcard.
  2. Carefully measure and draw a grid 1cm by 1cm on the image or on tracing paper on top.
  3. Label the columns across the top A, B, C and so on. Label the rows down the side 1, 2, 3 and so on.
  4. Add some diagonal lines through the corners of the squares.
  5. Decide how much bigger you want your new drawing to be – x 2, x 3, x 4 or more.
  6. On a new piece of paper, measure and lightly draw another grid at the larger size (2cm by 2cm, 3cm by 3cm, or 4cm by 4cm or more).
  7. Label the columns and rows to match the small image and add the diagonals.
  8. Draw what you can see in each square of the small original in the matching square on the large paper. Go one square at a time and use the column and row labels to find the right square – for example A1, C10, D5.
  9. When you have finished copying, if you want you could rub out your grid or ink or paint the new image to make it stand out.

You can use the same method to make an image smaller.