1. Thick and thin line technique
Imagine there is a spider on one of the surfaces of the 3D object. If he crawls onto another surface and you can still see him then that line should be thin. If he crawls onto the next surface and you can’t see him then that line should be thick.
All external lines = THICK
Used for an edge where only one surface can be seen
Most internal lines (but not always) = THIN
Used for an edge where both surfaces can be seen

2. By applying different TONES to a drawing you can make the object look more three dimensional
Using SHADING, LINES AND DOTS the closer you draw the lines or dots together of the harder you pres the darker the TONE is

3. Curved surfaces, the amount of light reflected gets less as the surface turns away from the light source and therefore the tone you use needs to be darker. A HIGHLIGHT should be used, a white area, that is closest to the light source
You can use SHADOWS on drawings to increase the feeling of depth and to suggest the object is resting on a surface. A shadow will be an elongated shape of the object, it will be on the side furthest away from the light source and will be darker than the darkest tone on the object.

4. TONE = the various shades that can be produced from one different colour
SHADING = a technique used to show how light falls on an object
HIGHLIGHT = a bright area where light is reflected from the edge or surface of an object
SHADOW = a dark area formed when an object is in the way of rays of light

5. WOOD – drawing curved lines on the end to represent growth rings and straight lines on the sides to represent the grain. Use a combination of brown, yellow and orange
MATT METAL - a series of straight lines can create a hard effect, altering the distance between the lines gives lighter and darker tones.

6. CHROME METAL – reflections appear as high contrast areas of dark and light
TEXTURED PLASTIC – represented by drawing small, irregular shapes over the required area.
CONCRETE – represented by a series of dots and small irregular shapes

7. SHINY PLASTIC – draw a number of short parallel lines across the surface or shade the surface evenly and rub out wavy lines
GLASS AND CLEAR PLASTIC – shade the suface using a light blue pencil and then rub out areas to suggest reflections. Feint broken lines can be used to show details that can be seen through the glass or plastic.