Raster (bitmap) logo files are necessary with some caveats
When your nifty new logo is designed, you’ll want to use it in a variety of sizes, some small, some large. Shouldn’t be a problem – as long as you have a vector version to work with. Because vector based files are based on mathematical equations, they can be used at any size. Vector file formats ALWAYS output at the highest resolution of the device you’re using to print with, so you’ll always be assured of the best reproduction quality available.
While vector based versions of your logo can be enlarged without any image degradation, bitmap images must be used at the same size (or smaller) than the original ‘source’ file. If you attempt to enlarge a pixel based image, it will pixelate (the actual pixels that make up the image will become visable). In practical terms, this will lead to your logo appearing ‘blurry’, dirty or fuzzy (below).
Because they are created using tightly packed pixels, these images (.JPG, .PNG, .TIF,. .BMP) must be in the resolution of the output device that they’re being used on. On a monitor that equates to 72 dpi (Pixels or Dots Per Inch), but in offset printing that requirement balloons to a minimum of 266 dpi. What’s the problem? Well, Pixel based images should not be enlarged (see above right) as the Pixels will be visible. Simply changing the print resolution of a72 dpi image to a 266 dpi image will NOT address this problem – you’ll still end up with the effect seen in our diagram. What does this mean in real terms? Well, lets take an full screen image from the web at 600 Pixels wide at 72 dpi screen resolution. That translates to approximately 11 inches total width. When converted to 266 dpi that image can be only be used to a maximum of 3 inches wide in a traditional print job such as letterhead and business card design (many quality printers will recommend 300 dpi, further reducing our maximum size to 2.5 inches). How do we get around this? Simply go back to our vector version, scale it the to the size required (or larger), and create a bitmap image from that. The same principles apply to logos that only use two spot colors as well. Here’s a look at our example logo, this time featuring red and black in a bitmap format. If we try to enlarge it, the image degrades rather significantly. And we’ll need four color printing to reproduce it.
So why do we need pixel based bitmap versions of our logo at all? Any form of electronic reproduction (i.e.: adding your logo to website or blog layouts, as well as using it on social media networks) cannot use vector based images (with the exception of Flash animations which utilize vectors) but requires bitmap formats like .GIFs , .PNGs and .JPGS. Because of the way they’re created, pixel based bitmap images lend themselves to special effects more readily (although this can create reproduction problems and a skilled designer can create special effects using vector images.) Also, many office software products utilize pixel based images when importing artwork. At the end of the day, we still need pixel based bitmap versions of our logo, but these should always begin life as our vector image.
In practical terms – what does it all mean?
What does all this mean in real terms? Well, let’s take a print job. Say, your spiffy new letterhead design. In our hypothetical world our printer charges setup fees of $10 per negative per color, $10 per plate per color and $100 per print run per color. With properly prepared vector spot color artwork, we’re going to need 2 of each, for a total of $240.00. Pixel based artwork is going to cost double that. At least. Many print shops bill a surcharge for a CMYK four color process setup, as well as cleanup. Also, you may have to print your Pixel based artwork on a larger press. So, doubling your charges may be on the conservative side. Amortize that over letterheads, envelopes, brochures and you’ll see that the nifty cheapo logo that saved you a few bucks in the logo design process, is going to cost you large in the long run.
No vector version available?
What if you don’t have a vector version of your logo? You’re going to have to get one. A skilled designer can convert a bitmap image to a vector format, but it requires skillful hand tracing and editing and even then may not result in a completely accurate version of your logo. Auto tracing images via software is hit and miss. Usually closer to miss. There are companies (such as The Logo Factory) who specialize in logo repair services – taking a low resolution bitmap image and creating the proper and necessary logo file formats. This service obviously results in extra charges.
Better off doing it right from the get-go.