Color Gamuts

• The range of possible colours within a colour system.
• Print: Inks
  • CMYK, even CMYKOG (Hexachrome)
  • Spot colour
• Web: RGB

Color

• Inks
  • CMYK
  • Spot colour
• RGB
  

Printing Ink

• Two parts
  • Pigment or dyes for colour
  • Vehicle to adhere colour to paper
    • Linseed oil, soybean oil, mineral oil or petroleum
    • Further adhesion from resins or other binding agents

Printing Ink

• $10-billion per year global industry
  • 150,000 copies of an 80-page magazine requires about 68 gallons of ink
    (From Chemical & Engineering News, 1998)
    

Two types of printing ink

• Opaque
  • Covers colour underneath
    • Paper or ink
• Transparent
  • Lets colour through to create various colours, tints and shades.
    • Process colours

Other ink variations

• Quick drying for high-speed production
• Metallic inks such as gold & silver
  • May contain copper, brass (alloy of copper and zinc) and aluminum-based pigments
  • Toxic or heavy metals in inks are environmental issue
    • Those in metallic inks not considered a hazard
• Fluorescent that glow
• Perfumed
• Slow drying for newspapers
  • Easily washed off press
  • Working toward water-based ink.
• Hardening inks to prevent rubbing
• Heat and light sensitive inks that change colour.
• Electronic ink (e-ink), but not really ink (circuit board using batteries).

Colour

• Important component of visual communication
• Colour for sake of colour worse than no colour at all
  • Successful use requires correlating use with the objective of publication.

Reasons for using colour

• Attract attention
• Create mood
• Eye appeal
• Accent and contrast
• Direct reader through message
• Create identity or association
• Aid retention

Colour to attract attention

• Major use.
• Applied to design elements of greatest importance.
• Placed with discretion.
  • Cluttered or loud colour detracts from message.

Colour to create mood

• Sometimes guided by nature, but other times by culture

Colour to develop associations

• Associate with products
  • Coca Cola red
  • Kodak yellow
  • Big Blue (IBM)
• Associate with life (Red Cross), moods (blue), or attributes (envy).

Colour to aid retention

• Colour has high memory value.
  • A colour should predominate because it helps readers remember what they saw.

Cost of using colour

• Cheapest use is colour paper.
• Spot colour--adding individual colours.
  • Increase impact of printed piece.
  • Usually for single graphic elements.
  • Used to emphasize illustrations, type, initial caps, or rules.
  • Often a pre-mixed Pantone colour.

Variations with one colour

• With one colour of ink, simultaneous printing of the solid colour and various tints achieved by screening:
  • Applying colour in dots in varying size and density,
• Or printing type, tint blocks and art from screened negatives
• White of paper creates tint.

Shading You can also shade, or add black, to a solid colour.           This wheel shows how one color can be shaded (outside layers) or tinted (inside layers)

More on colour

• See the Poynter Institute's Website on colour
  • http://poynter.org/special/colourproject/index.html
    
    

Mixing inks Inks can be mixed by printing process Dots of ink blended by the human eye.
Inks can be premixed by the printer or manufacturer Premixed according to Pantone Matching System.

Ink coverage

• Colour ink on colour paper can change colour on the paper.
  • Opaque ink for truer colour on colour paper.
  • Process ink (transparent) will change colour on the coloured paper.
    

Process colours

Four-colour line art. Process inks used Note uniform pattern of dots No daisy pattern

• Five-colour runs
  • 4-colour process, plus 5th colour not derived from process colours
    • Metallic gold, silver, Gator orange.
• Six-colour runs
  • All of above, plus 6th colour
    • Generally a spot colour for a border or headline.
  • Hexachrome
  • Dark/Light 6C & 8C
    

Hexachrome 6-colour gamut of CMYKOG Orange and green added to CMYK Can achieve 90% of PMS colours

Pantone Matching System System of colour mixtures The standard for colour printing. Available in inks, paper, overlay film, marking pens. Pantone library is in InDesign. Printed samples show colours as they will appear on coated, uncoated papers, etc. Includes metallic and fluorescent inks

Spot Colour vs CMYK There are CMYK approximates to PMS. Not always 100% accurate

Physics of colour

• Colour comes from sunlight
  • Visible part of electromagnetic spectrum
  • Reflected ray is colour we see.
    
    

Colour Terminology

• Hue--Colour.
  • Tone--Variations of hue.
• Value--Relative darkness, lightness of colour.
• Shade--Adding black to darken.
• Tint--Adding white (paper) to lighten.
• Chroma--Colour intensity:
  • Pigment saturation
  • Tendency to move toward or away from gray.
    

Psychology of colour

• Warm colours advance
  • Red, yellow, orange.
    • Reds dominate and can overpower.
• Cool colours recede.
  • Blue, violet, dark green.

Tips for using colour

• Black type on white or pale yellow is best for readability.
• One colour should dominate
  • Any other should be used for accent or contrast.
• Warm colours are higher in visibility than cool colours.
• Colour tints behind text make the information stand out.
  
  

Balance

• From proper placement of elements by weight or visual emphasis.
  • Colour adds further weight, according to hue and value.
    

Rhythmic use of colour

• Achieved through repetition at points in the printed piece.
• Spots of colour can be used
  • To guide reader's eye through the message
  • For rhythm.

Background colours

• Silver is good background colour
  • Provides
    • High contrast and
    • A sophisticated look.
  • Expensive in print
  • May require another run through the press for a coating of special varnish to prevent smearing.

Body type

• Body type in any other colour is rarely as good as black on white.
• Also effective (depending on objective):
  • Brown on buff
  • Blue or green on some shades of off-white
  • Use sparingly:
    • Best limited to occasional captions or other small areas that require special contrast
• White text is usually not ink

Display type

• Especially effective in colour.
• Contrast to certain words in title
  • For attention and
  • Communication value of words.

Other applications of colour

• Rules and borders
  • Can separate and draw attention to panels of text.
• Typographical dingbats
  • Get special attention through colour
  • Create rhythm
• Initial letters, stars, bullets, squares, etc.
• Surprinting colour type over illustrations.
  
  

Computer colour modes

For print: CMYK
For Web: RGB 256 index colours 216 browser-safe colours On web, value is intensity. RGB indicated by values (0-255) or percentages. Or hexadecimal codes (hex triplets) 00, 33, 66, 99, cc, ff

X11 Colour Names

• 140 colour names using RGB combinations used on modern computers.
  • Also bear hex triplet notations but not merely web-safe colours.
  • To see X11 chart and hex triplets: http://msdn.microsoft.com/en-us/library/system.windows.media.brushes(VS.85).aspx

For further study: http://www.worqx.com/colour/index.htm

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