Confessions of a File Master
Everything you need to know about setting up files for print or the web.
Have you ever wondered what the best practices are when setting up files for print and web? No? OK, my blog is done…
I’m well short of my five hundred words, so I better continue my discussion…
CMYK v. RGB
Let’s start with color space. It’s essential to know when to use CMYK versus RGB colors on your project. First, let’s break down what those acronyms mean:
- CMYK: Cyan, Magenta, Yellow and Black. Back in the printing press days when we used plates, printers referred to the black plate as the “Key” plate, because it carried the important key information relating to the artistic detail. Hence the K in CMYK.
- RGB: Red, Green and Blue
When choosing between the two, here is a good rule of thumb – anything dealing with the web should always be in RGB, while printed materials should be in CMYK. But few designers and clients know why this is the standard.
If we again go back in time to the days of printing presses were used, each ink color was placed on a separate plate. The printer would lay down one color, wait for it to dry, lay down another color, wait for it to dry and so on until all four colors were complete.
Printing presses still work on that same theory, with an exception. Offset printers now offer a “spot” color, which they use to achieve a specific color swatch, usually a Pantone color. As the printing age has progressed, the digital printer has come a long way, allowing it to print in RGB as well. But the standard still stays the same – use CMYK on all printing needs, as the color will appear differently if printed in RGB.
While colored ink is CMYK, computer monitors give off colored light called RGB. Computer monitors have a larger color gamut than printing, which is why a computer displays a million more colors than what you will see with printing. Printing deals with absorption and reflection of wavelengths, which we perceive as color (CMYK). Because of printing’s limited color gamut, a lot of times clients will note that something looked different on screen than it does on paper. This is because of the different color ranges that a computer monitor and printing allows.
Vector v. Raster
(No, not talking about “Despicable Me.”)
There are two main types of image files: Vector and Raster.
- Vector: Created with vector software, these files are often used to print an image on a physical product, like a logo printed on a t-shirt
- Raster: You create raster files with pixel-based programs or by capturing them with a camera or scanner. Widely used on the web, these files are commonly found as jpg, gif, and png files.
A vector image is one that is constructed using continuous curves with mathematical formulas, not color blocks. Vector images do not have a resolution, which is an expression of dots per inch. This means that are scalable to any size without resolution loss.
You construct raster images using solid color blocks called pixels or dots. The number of pixels/dots in a raster image is expressed by how many are within one square inch (i.e., 300 dpi means that there are 300 dots within a one-inch space). This is also how we express resolution. Resizing a raster image doesn’t add more pixels – it just makes the pixels bigger. The result is “pixelation,” or those terrible, ragged edges.” For this reason, do not enlarge a raster image from its original size.
We aren’t all typographers, but…
Apostrophes and Quotation Marks v. Prime Symbol
One of the most common typography mistakes is the use of a prime symbol as apostrophes or quotation marks and vice versa. You may ask, what is a prime symbol? A prime symbol is the symbol used in mathematics or measurements as the abbreviation of a foot mark or inch mark. We use an apostrophe to form contractions or to show possession. Quotation marks start and end a quote. It’s commonplace to see these mistakes on TV, the web and in print.
In conclusion, use CMYK for print and RGB for the web or TV. Vector images don’t have a resolution and raster images are pixel-based. And try to remember to use apostrophes, quotation marks and prime symbols in their proper case.