When you order products that require your logo to be printed, you will need to supply your artwork in a specific format depending on how your logo will be printed.
Firstly, let’s look at the 2 main formats:
Bitmaps are images that are made up of tiny blocks called pixels. Each pixel stores the colour information at that particular part of the image. Let’s say you have a bitmap image that is 1000 x 1000 pixels in size that means there are 1000000 pixels in total that make up the image.
Bitmaps are the best format for storing photographs as they tend to be very complex images containing thousands of different colours. If you want to print a bitmap onto a product though they are not the best choice. If you only have a low resolution bitmap then the quality will suffer and the final print can look “pixelated”. In addition to this many products use a printing process called screen printing which only allows for vector images.
Common bitmap file formats: BMP, JPG, PNG, GIF
Vector images are file that contain images represented as a set of mathematical data which describes lines and curves. So all the data essentially tells a computer how to draw the image. The advantage of a vector image is that it a resolution independent, meaning they can be drawn at large sizes with no loss of quality.
The disadvantage of vector images is that they are only good for simpler images with flat colours, so they can’t used for photographic images effectively.
In the world of promotional products vector images are ideal and often required due to the printing process involved. And because logos tend to be quite simple they can be represented with a vector image easily.
Common vector file types: SVG, EPS, AI
Bitmap and Vector image side by side
To see clearly the difference between a bitmap and a vector, look at the image below. The left image is a low resolution bitmap blown up to a larger size, and the right hand image is a vector graphic where it doesn’t matter how big you make it. You can see the individual pixels that make up the bitmap on the left.
Why is the number of colours important?
You’ll often be asked how many colours you want to print onto a product when enquiring about promotional products. This is due to way a lot of promotional items are printed onto, using something called screen printing.
This is where each colour in your logo is separated onto different plates or screens. These are then transferred individually onto the product. So for every colour in your logo a separate screen must be set up which increases the cost of production.
Some products can be printed onto digitally in which case bitmaps can often be used as well, however it’s still best to go with a vector image where possible to ensure the best quality imprint.