# THE GRID – Creating Optical Illusions

Students use metallic coloured pencils on black construction paper and follow the instructions on The Grid worksheet to create a geometric design that gives the illusion of movement.

80 Minutes

Mathematics
Visual Arts

#### Vocabulary

2-dimensional 3-dimensional contrast op art optical illusion

#### Materials

Rulers Pencils Construction Paper - Black - 20.9 cm x 30.5 cm (9" x 12") Coloured Pencils - Metallic Coloured Pencils - White

## Steps

### Step One

1. Use a white coloured pencil to draw a square about 18 cm x 18 cm.
2. Mark spaces of 1.5 cm on opposite sides of the square.
3. Draw a straight line from the centre of the top of the square to the opposite side.
4. Mark spaces of about 2 cm on the centre line.

### Step Two

1. Start at the centre of the top of the square.
2. Mark spaces that gradually get further apart as they move to the outer edge of the square.
3. Repeat the same spaces on the bottom of the square.
4. Draw straight, vertical lines from each mark on the top of the square to the mark directly opposite it on the bottom of the square.

### Step Three

1. Mark a line ‘a' about 4 spaces left of the centre.
2. Mark a matching line ‘b’ on the right of the centre.
3. Mark spaces on the 'a' and 'b' lines to match the spaces on the sides of the square.
4. Draw horizontal lines across the square to connect the marks on either side.
5. When you get to the ‘a’ line change the angle and draw a diagonal line down to the mark one space LOWER on the centre line.
6. When you get to the centre line change the angle again and draw a diagonal line up to the mark one space ABOVE the centre line.

### Step Four

1. Colour alternating rectangles using one metallic colour.
2. Place a ruler along the edge of a rectangle and colour against it to get a clean line.

### Step Five

1. You may want to draw a small design in each black space using a different metallic colour.

## Learning Goals

Students will be able to:

• create a geometric design that creates the illusion of movement;
• use contrast to create an alternating pattern;
• follow written instructions to accurately complete an op art design.

## Extensions

Have students:

• complete one of the following lessons available on this website:
Op Art
The Bulge
Sphere Me
• share their work with their peers.

Vasarely
Vasarely2
Tousignant
Riley

## Introduction

1. Display the op art images.
2. Discuss the works and make a list of characteristics of the art style, for example,
- although the works are flat they fool the eye into thinking they are 3-dimensional, or actually moving
- a mathematical form of art based on geometry
- non-objective
- uses contrasting colour, line and shape to create a sense of movement
- uses perspective
- positive and negative spaces are equally important
3. Introduce the challenge.

## Activities

### The Challenge

1. Create a geometric design that creates the illusion of movement.
2. Use contrast to create an alternating pattern.
3. Follow written instructions to accurately complete an op art design.
4. Demonstrate technical accomplishment.

### The Process

1. Guide students through the steps outlined in worksheet.
2. Establish success criteria with your students, for example,
I know I am successful when I have:
- measured carefully
- created an accurate op art grid design
- used strong contrast
- kept the paper in good condition
3. Observe students as they work.
4. Encourage them to share and expand on each others' ideas.
5. Provide individual assistance and encouragement.

## Sharing

1. Place students in small groups and have them share thoughts about the work.
2. During the discussion include references to:
colour - how colour intensity and contrast affect the overall impact of the work
- technical accomplishment - how the condition of the paper, careful measurement and attention to detail affect the overall impact of the work
3. Ask students what they found satisfying about doing this project and why.
4. Ask them what was difficult about doing this project and why.

## Assessment

1. Observe students as they work – thoughtful focus, discriminating, seeking more information, elaborating, experimenting.
2. Observe students as they discuss the designs – active listening, insightful contributions, supporting ideas with evidence found in the artwork and from personal experience.