Pixels? Inches? Centimetre? Millimetre? Length? Breath? All this print stuff confusing you? In this blog we’ll ensure that you understand print dimensions for best results. Before we progress, there are certain jargons we need to understand. Let’s look at some of them.
What is PPI – Pixels per Inch?
PPI describes the resolution in pixels of a digital image. pixel stands for picture elements. Each pixel has sub-pixels which are RGB colour compounds. There are a fixed number of pixels that a screen can display and the density of pixels within a digital image. A digital image with a higher PPI tends to be of higher quality because it has a greater pixel density, but exporting at 300 PPI is generally considered industry standard quality.
What is DPI – Dots per Inch?
Printers reproduce an image by spraying tiny dots onto the print surface, and the number of dots per inch affects the amount of detail and overall quality of the print. When your digital design or image is going to be physically printed, DPI is considered. So, from a printer’s perspective DPI is important. DPI uses the CMYK (cyan, magenta, yellow and key/black) colour model to control the amount of red, green, and blue light that is reflected from white paper. Each model and style of printer produces its own unique DPI based on its settings. Inkjet printers produce a resolution around 300 to 720 DPI, while laser printers produce images anywhere from 600 to 2,400 DPI.
Important to know:
- There are no standard dot size or shape in DPI’s.
- Higher DPI does not always equate to a higher quality print.
- FYI Books and magazines use 150 DPI for photographic reproduction, and newspapers use 85 DPI.
What is Dithering?
A printer translates pixels into a series of dots in order to reproduce on the print surface. This process is known as Dithering. To print, pixels ought to be converted to dots, simple!
Important to know:
- Absorbent paper surfaces and uncoated recycled paper allows for droplets of ink to spread; hence a larger dot pitch is used.
- As you reach larger print formats, visual acuity becomes important to consider. If the print is viewed close up then one may choose the printer device limits. However, if a poster, banner or billboard is viewed from far then you may use a lower PPI.
Why size is important when printing?
Most printing services, will require a certain density of PPI to be able to render a print that looks good with smooth colour transitions.
General thumb rule to follow. If you want to print a 4 x 6-inch image at 300 PPI, then you need a file that has at least 4 x 300 (1200) pixels along its short side and 6 x 300 (1800) pixels on the long side. In other words, it needs to be at least 1200 x 1800 pixels in size.
Therefore, when cropping and sizing an image for printing, you’ll need to know what PPI the image should be. Please ask the A2 staff for details before your print.