When dealing with designers you might get asked to supply your images as ‘hi-res’. Firstly we need to define what is a high resolution (hi-res) image and a low resolution (low-res) image and what to use and when. So what are High Resolution and Low Resolution images?
These are images that are 72dpi and normally have an RGB colour setting. They are formatted for screen use (such as websites and social media).
Traditionally these are images that are 300dpi (at actual size) and above. These are formatted for use in the print industry and are normally have a CMYK colour setting. The required dpi (dots per inch) for printing is higher than needed for your screen, so even though the image looks fine on your monitor when printed, this might become blurred or pixelated, like the example below.
On-screen When printed
So the main difference between the 2 formats is that hi-res images are used mainly for print and large format graphics, which requires more dots per inch (dpi) than low-res images which are mainly used for screen and can be as low as 72dpi.
Of course, there are always exceptions to the rules in that now with the introduction of higher resolution monitors and displays your images might need to be a higher resolution (or contain more pixels) than the standard 72dpi.
Another thing to bear in mind is when you are purchasing images from an online image library (such as iStockphoto, Shutterstock), the cheapest option is not always the best.
We would always recommend that you purchase the highest quality image possible (or largest file size) as this will save you having to go back and buy the higher quality version at a later date if you decide you want to use an image you have selected for your website in a brochure or annual report etc.
If in any doubt always send a hi-res image to the designer, they can then resize or crop down to the size needed from this, whereas a low-res image’s resolution cant be scaled up or increased as this would cause it to blur or pixelate.
Hi-res images – 300dpi and above, used for the print industry, large file size, high quality
Low-res images – 72dpi – 150dpi, used for screen applications, small file size, low quality