Designing a motif – Motifs and Patterns on the Computer (Senior 3 Fine Arts) | Ganzaa

Motifs and Patterns on the Computer

Lessons

Senior 3 · Fine Arts

Motifs and Patterns on the Computer

4 lessons

Lesson 3 of 4

Designing a motif

25 min

Small enough for a stamp, strong enough for a wall

A good motif must work at every size. Printed 1 cm high on the edge of an exercise book, it must still be recognised. Repeated a hundred times across a curtain, it must not become a blur. That is why designers spend most of their time on the motif itself, simplifying and testing it, before they ever make a pattern. In this lesson you will design one motif on the computer, from the simplified sketches on your source sheet from Lesson 1.

Definition

Symmetry: an exact match between parts of a design. Reflection (mirror) symmetry matches two halves across a line. Rotational symmetry matches copies turned about a centre point; its order is the number of copies in one full turn.

Positive shape: the shape you draw. Negative space: the background space around and inside it, which also forms shapes.

Boolean operations (path operations): commands that combine overlapping shapes into a new one. Union joins them; Difference cuts the top shape out of the one below; Intersection keeps only the overlap.

Colour palette: the small set of colours chosen for a design, for example three.

What makes a strong motif

A clear silhouette. If you filled it solid black, would it still be recognised?
Balance. Symmetry is the easiest way to get it; asymmetry can work but needs care.
Few colours. Two to four colours print cleanly and recolour easily.
Good negative space. The gaps are part of the design; in imigongo, the white ground between ridges is as important as the ridges.
A link to the source. Someone who knows agaseke or imigongo should see the connection.

Symmetry on the computer

Figure 1. Symmetry in motifs. Reflection mirrors a shape across a line; rotational and radial symmetry turn copies round a centre point by equal angles.

The computer makes symmetry exact. For reflection, draw half the motif, duplicate it (Ctrl+D) and flip the copy (H), then move it so the two halves meet on the mirror line. For rotation, draw one part, set its rotation centre to the middle of the motif, and rotate copies by an equal angle. For a motif with rotational symmetry of order $n$ , each copy turns by

\text{angle} = \frac{360^\circ}{n}

Building a motif, step by step

Figure 2. Building a radial motif inspired by an agaseke lid: draw two basic shapes, rotate copies about the centre, combine them, then colour and place the motif on a tile.

Set up. Make a page 60 mm by 60 mm, show the grid and turn on snapping. Use guide lines through the centre.
Draw basic shapes. A circle 36 mm across at the centre and one triangle above it, made with the Star and polygon tool set to 3 corners (Figure 2, step 1).
Rotate copies. Select the triangle, click it again to show the rotation arrows, and drag its small cross (the rotation centre) to the centre of the page. Duplicate (Ctrl+D) and rotate the copy by $45^\circ$ in Object, Transform, Rotate. Repeat until there are 8 triangles (step 2).
Combine. Select the 8 triangles and the circle and choose Path, Union, so they become one shape. Draw a small circle at the centre, select it with the star and choose Path, Difference to cut a hole (step 3).
Colour. Choose a palette of two or three colours, here dark brown and straw, taken from the source. Place the motif on a square tile of the background colour (step 4).
Save versions. Save as motif01.svg, then try changes in motif02.svg, so the original is never lost.

Testing the motif

Test	How	What it tells you
Small-size test	zoom out until the motif is about 1 cm on screen, or print it that size	whether thin lines and small gaps disappear
Silhouette test	fill a copy solid black	whether the outline alone is recognisable
Squint test	look with half-closed eyes from 2 m away	whether the light and dark areas are balanced
Black and white test	switch the colours to greyscale	whether the colours differ enough in lightness

Make at least three versions of your motif, for example a positive version, a reversed version (light on dark) and one with an extra detail, and keep the one that passes all four tests.

Worked example 1: angles for a radial motif

Mukamana wants 12 petals round the centre of her motif. By how many degrees must each copy turn, and what will the last copy's total rotation be?

Step 1 $\text{angle} = \frac{360^\circ}{12} = 30^\circ$ .

Step 2 The first petal stays at $0^\circ$ , so the 12th petal is turned $11 \times 30^\circ = 330^\circ$ . One more turn of $30^\circ$ would bring it back to $360^\circ$ , on top of the first.

Answer. $30^\circ$ each; the last copy is at $330^\circ$ .

Worked example 2: fixing a motif that fails the small-size test

Nshuti's imigongo-inspired spiral has 7 thin turns. At 1 cm the turns merge into a grey blob.

Diagnosis. The lines and the gaps between them are too thin to survive at small size.

Fix. Reduce the spiral to 3 turns and make the line and the gaps equal and much wider. The character (a turning spiral) is kept, and the motif now reads clearly at 1 cm.

<em>Easy Way to Duplicate Objects Around a Circle in Inkscape</em>, from Davies Media Design. It shows a faster method (the Rotate Copies effect) for the step 3 rotation; compare it with the Transform method in this lesson.

Warning

Wrong rotation centre. If copies fly off in a wide circle, the rotation centre is still in the middle of the triangle. Move it to the centre of the motif first.

Too many details. Fine lines and tiny dots disappear in print and clog a screen print. Simplify.

Tip

Draw one, copy the rest. Build one part well, then let the computer repeat it exactly: duplicate, flip, rotate, union.

✦

Practice

What is the difference between reflection symmetry and rotational symmetry?

A motif has rotational symmetry of order 6. By how many degrees is each copy turned?

Which path operation would you use to cut a round hole in the middle of a star?

Why should a motif usually have only two to four colours?

Ingabire's motif looks fine on screen but disappears into a grey patch when printed at 1 cm. Suggest two changes.

Evaluate this motif: a realistic photograph of a cow pasted on a square. Is it a strong motif for a repeating pattern? Give two reasons.

Design task. Build a motif from your source sheet using at least two of: duplicate, flip, rotate, union, difference. Make three versions and run the four tests.

Show answersHide answers

1. Reflection matches two halves across a mirror line; rotational symmetry matches copies turned about a centre point.

2. $\frac{360^\circ}{6} = 60^\circ$ .

3. Difference: put a circle over the centre, select both and choose Path, Difference.

4. Few colours print cleanly, keep the design clear and make it easy to produce colour variations.

5. Remove fine details; thicken the lines and widen the gaps; reduce the number of turns or parts.

6. No. A photograph is a raster image with lots of detail, so it will not stay sharp or read at small size; it has no clear silhouette or flat colours, and it does not simplify the source. A stylised cow's head or horns in flat shapes would work better.

7. Check: the source is credited; tools used are listed; three versions saved; test results written beside the chosen version.

Reflection

Compare your final motif with your first sketch. What did you take away, and what did you keep so the source can still be recognised?

Sources and credits

Lesson text, Figures 1 and 2, table, worked examples and practice: written by Ganzaa. Menu names follow Inkscape, a free and open-source program (inkscape.org).
Video: Easy Way to Duplicate Objects Around a Circle in Inkscape | Rotate Copies LPE, Davies Media Design, embedded from YouTube.

1Small enough for a stamp, strong enough for a wall

2What makes a strong motif

3Symmetry on the computer

4Building a motif, step by step

5Testing the motif

6Reflection