Comics Tutorials – Raster/Vector, RGB/CMYK

Two kinds of graphic formats are used in electronic mediums. Raster and Vector.
Raster graphics are stored as a bunch of pixels, while Vector graphics are stored as a bunch of shapes and nodes.Raster graphics start losing their clarity as they are stretched beyond their original maximum size. Vector graphics can be (theoretically) stretched to any size without loss of clarity.Vector graphics van also be used to draw precise shapes, since each stroke can be tweaked separately. But Raster graphics have a better color reproduction. Photoshop and GIMP are examples of Raster graphics editors.
Illustrator, Inkscape, CorelDraw are some of the vector graphics editors.
Vector graphics can be exported to raster graphics.Inkscape is a open source, free vector graphics editor I use for lettering. More on this in the workflow discussions.
The Graphic novel making – Difference between RGB and CMYK formats Many of you must have read these terms ‘RGB’ and ‘CMYK’ in my previous post, and wondering just what they are.Well, RGB and CMYK are 2 models of representing color. Typically, RGB model is used in web and screen colors, while CMYK is almost exclusively used in print medium.The following graphics show the color models in their representative form.
RGB

AdditiveColor

CMYK

Color-subtractive-mixing-cropped

The abbreviation RGB stands for Red-Green-Blue. Every color pixel that we see on a computer / TV screen is a combination of various quantities of these three primary colors. When these three colors are mixed at their full strength, the color white is produced. That’s why, sometime these colors are called ‘Additive colors’.Printing is a different ball game, though. When printing on paper, the printers use inks of CMYK combination. CMYK stands for Cyan-Magenta-Yellow-Key. Cyan, Magenta and Yellow are the three ‘Subtractive Colors’ i.e. adding them together yields black color.Every color printed on paper is a combination of CMY colors in various quantities. The ‘K’ in ‘CMYK’ stands for Key, which is a term used for black color. The reason the letter ‘B’ is not used for black is to avoid confusion with Blue in the term ‘RGB’.Black color is separately mixed along with CMY combination while printing. Even though combining CMY colors yields black, it may not be a very neat effect due to impurities in inks, and any discrepancy on a black print is easily visible on paper. That’s why black is treated as a separate color and printed so.

The reason CMYK combination is used for printing on paper is why sometimes paper printing in color is sometimes referred to as ‘Four color printing’.

Sometimes, there’s a need to use a special color in very precise quantities while printing. This is achieved by adding the ink for that special color to the printing process. This is called ‘Spot Coloring’.

The color spectrum within CMYK world is not as rich and diverse as that of RGB. That’s why it’s quite possible that an image appearing brightly colored on screen may not be reproduced as it is on paper (on professional printers). The inkjet and laser printers may produce this RGB effect accurately, but the professional offset printers will not.

It’s very important that all colored images to be printed on paper are converted to CMYK format before being sent to the printer. Since CMYK has a much lesser range of colors, it may be difficult to visualize how the image will look on paper when viewed in RGB mode.

The following two images show the subtle color difference in RGB image and CMYK image.

RGB
cover_rgb
CMYK
New Bitmap Image

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