This project shows how an outwarded triangle can appear to pop out in 3D, even though it actually goes inward. Using reverse perspective, simple lines and shading trick the brain into seeing depth that isn’t really there.

In this Instructable, I’ll show how to build this optical illusion wall art using basic materials like cardboard and markers. The result is a modern decorative piece that grabs attention and makes people look twice.

Supplies

For this amazing craft you will be needing

Paper or Cardstock
Scissors
Colors
Sharpie
Pencil
Ruler

Step 1: Make a Cross

Using a ruler, draw two diagonal lines from corner to corner, forming an X across the cardboard or paper. These guidelines will help keep the triangle centered and symmetrical.

Make sure the lines are straight and meet exactly in the middle.

Step 2: Make Middle Box

On the longer diagonal of the X, measure and draw a 3-inch line. From the end of that line, draw a 2.3-inch line upward to form a right angle. Complete the shape by connecting the lines to make a box.

Use the ruler to keep all lines straight and accurate.

Step 3: Draw Dot

At the point where the two diagonal lines of the X cross, mark a small dent or indentation. This will be the center of your inverted triangle and helps guide the depth of the illusion.

Step 4: Make Fold Flaps

Draw a mark like 0.75 of an inch above the middle in the vertical way. Place your ruler so that one end is on the dot you marked. Angle the other end toward the corner of the box that faces inward along the long side of the X. Draw a line over. color in the tiny space in each because we don't need it. Then draw a dotted line facing inward for cutting over.

This line will guide you in creating the inward triangle shape for the 3D illusion. Make sure the ruler stays straight and precise.

Step 5: Make Border

Make a border vertically so it matches height of the horizontal. Then color it in.

Step 6: Draw in Middle

Inside the middle square, draw any details you like, such as a door, window, bricks, or patterns. These details help sell the depth illusion and make the artwork more interesting.

Step 7: Add Side Panel Details

To create a door or TV on the right side panel, first draw a vertical line. Then, using a ruler from the middle dot, draw lines from the edge of the panel to the top of the vertical line to create a perspective effect.

Repeat the same process on the left side panel. These angled lines help give the artwork a stronger 3D depth effect.

Step 8: Create the Floor Effect

To make the floor look 3D, use the center dot as a reference point. With a ruler, draw lines from the edges of the floor area toward the center dot.

You can also place a few separated dots on the floor area and draw lines from them toward the center to add more depth and texture. These lines help strengthen the perspective effect.

Step 9: Ceiling

Just draw any lights or posters and there is no need to complicate due to it already bending.

Step 10: Color

Color everything in.

Step 11: Cut Lines and Fold

Carefully cut along all the dotted lines using scissors or a craft knife. These cuts allow the artwork to fold and form the inward 3D shape. After cutting fold in all the pieces.

Step 12: Fold and Glue the Flaps

Fold the small flaps inward and glue them to the back of the larger flaps, following the drawing. This will pull the shape inward and form the triangle needed for the 3D illusion.

Hold the pieces in place until the glue sets so the triangle keeps its shape.

Step 13: Voilà!

Your reverse perspective triangle art is complete. Mount it on a wall or display it flat and view it straight on to see the 3D illusion come to life.

Step back, adjust the angle, and enjoy the effect

Introduction: Reverse Perspective Art