The better the quality of your print files and designs, the better the overall quality of your products.
Creating the perfect file means there will be less of a risk of your order being delayed due to your design not meeting printing requirements.
The golden rule behind nailing your printable files is to follow the guidelines created by our in-house experts. We consulted Johnson Printings Graphics Team for tips that can help you be on your way to the perfect print file.
Printing Terminology
Print size is the actual size of the image as it’ll come out printed. It’s measured in inches or centimeters. Image file size is measured in bytes. It tells you how much space the image takes up on a disk or drive.
A pixel is a unit of measurement for digital images you see on a screen.
Pixel dimensions express the total number of pixels along a digital image’s width (vertical) and height (horizontal).
Resolution expresses the density of pixels or dots in an image. For printed images, resolution is expressed in DPI—dots per inch.
DPI (dots per inch) is a printing term. Digital devices display images in pixels, and printers print images in dots. DPI is calculated using your digital image’s pixel dimensions and digital image size. The higher the DPI = the more the dots = the sharper the print. The lower the DPI = the fewer the dots =
the blurrier the print.
To help you visualize the relation between dimensions and resolution, look at the 3 pictures above. The images have the same dimensions (width and height), but they have different resolutions (DPI).
VECTORS, RASTERS AND FILE FORMATS
One of the key consider
ations up-front is whether your artwork should be composed of vectors, rasters or a combination of both. This decision in turn determines the file formats you can use.
But what are vectors and rasters and why would you choose one over the other?
RASTERS
A raster is a digital version of a traditionally printed image. (ie. it is made up of a grid of colored dots that when viewed from a distance give the appearance of a seamless image.) This is just the same as the print that appears in books and magazines. If you look closely enough or use a magnifying glass, you can see that the image is made up of many tiny dots of ink.
In a digital file, the dots are in fact squares, and are known as pixels.
A vector is an object.
Vector artwork is art that's made up of vector graphics. These graphics are points, lines, curves and shapes that are based on mathematical formulas. When you scale a vector image file, it isn't low resolution and there's no loss of quality, so it can be sized to however large or small you need it to be.
RASTER VS. VECTOR
So, what are the pros and cons of each format?
Rasters can depict anything, from a simple geometric shape to the most complicated photographic image, but with one caveat: You must have enough pixels available to render a high quality image. We talked about resolution above.
Vectors on the other hand are excellent at depicting geometric shapes and solid or evenly graduated colors. The wonderful thing of a vector image is that because it’s lines or filled objects they can be scaled up or down to any size with absolutely no loss of quality.
It’s important to note that some file formats allow rasters and vectors to happily co-exist in the same file. Just remember that if you scale the file up the vector elements will continue to look crisp, but the raster elements may become pixellated or blurry.
Here’s a quick table of the various uses of rasters and vectors:
