Graphics Formats and Tips for Poster Printing
If you try to print a poster without proper understanding of graphics formats, you may be in for some trouble. The translation between your desktop and paper is not always what you expect or desire. Images that look great on screen will appear pixilated when used for poster printing, if the right adjustments are not made. Learning and using the proper programs and preferred graphics format for your project will insure graphics that look as stunning as you imagine.
Bitmap and Vector Formats
There are two types of graphics formats. The first type is a bitmap format. The second type is vector. While the majority of online images are created in the bitmap format, it is not preferred for creating images that you will eventually print. You can convert the file formats if you use the right program.
Bitmaps are composed of pixels (picture elements) in a grid. Each pixel holds color information for the picture. Their resolution is fixed and they do not re-size well. Some examples of a bitmap are JPG, JPEG, GIF, and TIFF. While bitmap graphics work fine for web images, they do not translate as well printed.
The vector format is resolution-independent, composed of individual objects made up of mathematical calculations. Vector images can be re-sized easily and still look good. Some examples of vector formats are EPS, CGM, PICT, and WMF. This is the best format for poster printing.
When you create your original designs like logos and posters, you should choose a vector format. They will re-size well and print in a crisp, professional manner. In contrast, the bitmap images appear jagged around the edges and fuzzy. The resolution required by commercial poster printing companies can only be retained in a vector format.
The type of color models you use will depend on the job. If you are creating an image to be used online, then RGB colors will work fine. RGB - which stands for red, green, and blue - will not translate well for poster printing. Commercial printers can only print using the CMYK model. Fortunately, you can easily change your color to CMYK before you print. CMYK - which stands for cyan, magenta, yellow, and black - combines the three subtractive primaries plus black to create any color that you desire. Most graphics programs have an option for switching between color models.
When you are choosing a graphics program, keep in mind the two types of graphics formats. Some programs work with one or the other, few of them work with both. For instance, Adobe Photoshop is one that works much more easily with bitmaps (it can do vector formats, but only the most recent versions and advanced tools) and CorelDRAW is one that works better with vector file formats. For poster printing, choose a program that works well with vector file formats.
You will save yourself from a number of headaches by choosing the right tool for the job. For web design, bitmaps, RGB colors, and Photoshop works great. When poster printing, use vector graphics, CMYK colors, and a program such as CorelDRAW or Illustrator, and you will end up with a much more professional poster design.