Colour, Resolution, File Formats
Monday, September 18, 2006

These are just a few of the notes from our class. Refer to your handouts for the full presentation.

Colour appeals to emotions, and has a more immediate impact


Monotones appeal more to the intellect and require more intellectual interaction by the reader (such as fine art photography using black and white or duotone images)


Copy: In this wonderful game, white and black always have been together. Stop racism.

Spot colour is used to highlight (information). In a black and one colour advertisement or image, use colour sparingly and only to highlight (a few key messages)


CMYK – Reflective Colour
Cyan, magenta, yellow, black - when printed on white paper create nearly the full spectrum of colours


CMYK is the standard for print

CMYK and Image Resolution
Because CMYK is used for print, the image resolution must be very high
> PPI (pixels per inch) or DPI (dots per inch) refer to the number of pixels per inch in a digital image
> For magazine ads use 300 ppi (150 line screen)
> For newspaper ads use 200 ppi (100 line screen)
> File formats for images used print are “.tif”, “.eps”

RGB – Luminescent Colour

Red, green and blue create the full spectrum of colour in luminescent colour
One common application of the RGB color model is the display of colors on a cathode ray tube, liquid crystal display or plasma display, such as a television or a computer's monitor. Each pixel on the screen can be represented in the computer or interface hardware (for example, a 'graphics card') as values for red, green and blue. These values are converted into intensities which are then used for display.

RGB and Image Resolution
> Because RGB is used for monitors, the resolution is low
> The maximum resolution monitors can show is 72 ppi (dpi)
> High definition television monitors will use more
> File formats for images used on the internet are “.jpg” or “.gif”
> Prepress does not allow the use or RGB images because they do not separate correctly to CMYK

Print Resolution Guides
72 ppi = 72 dpi - Photographs and graphic will look poor on any paper.
100 ppi = 100 dpi - Photographs and graphics will be acceptable on plain paper; however, printed on high quality paper will reveal flaws
144 ppi = 144 dpi - Photographs and graphics have to be very closely scrutinized to reveal flaws on any paper.
300 ppi = 300 dpi - Photographs and graphics printed at this resolution and will not reveal flaws that can be attributed to resolution
700 ppi = 700 dpi - Photographs and graphics printed at this resolution will look identical to those printed at 300 dpi. The added size of the file will not improve the quality of the image.

Color Wheel


> The color wheel shows the relationship of colors. There are three primary colors (red, blue, yellow)
> Three secondary colors which are the result of mixing primary colors (purple, orange, green)
> And the tertiary colors which are a primary color mixed with a secondary color such as red-orange, yellow-green and blue-violet
> When they colors are mixed with pure colors white or black it creates numerous different tints and shades

TERMS TO KNOW
> Hue: Another name for color
> Tint: Color + White
> Tone: Color + Grey
> Shade: Color + Black
> Value: The lightness or darkness of a color

Photoshop: Colour Mode

Under the IMAGE pulldown menu, select MODE, and you’ll see what colour mode your image is by the one that is check-marked


Here you can also make it a different colour MODE, such as CMYK, RGB, Grayscale and Indexed Color (used for .gifs)

Photoshop: Resolution (Image Size)
Under the IMAGE pulldown menu, select IMAGE SIZE… and you’ll see a dialogue box showing you information about your image size


Pixel Dimensions: the size of the image file
Width & Height: shown in both pixels and inches
Resolution: shows how many pixels/inch the image is

Photoshop: Selecting Pantone Colours
On your floating Colour Palette, click and hold on the small arrow on the top right hand side, and select Pantone Process Colors