Quick Guide to File Formats

Quick Guide to File Formats

Knowing what file format to use and send to people can be confusing and daunting for those who are not familiar with them. I myself as a designer have had numerous problems from receiving the wrong kind of formats from clients. This leads to unnecessary time being spent on projects, which is frustrating for both parties involved and also not forgetting more expensive, as time is money. I don’t expect clients to know the ‘ins n outs’ of all the different file formats, far from it, but I believe it is beneficial if they kinda got the jist of some of them. So I decided for my next blog post to write a brief handy guide to how and why we use different formats. I’ll try not too bore people to much… Hopefully it’ll be easily understandable and helpful if needed..!! 🙂


CMYK vs RGB – These two acronyms are the resolutions of colour used in the document. CMYK format is used for print and RGB is used for screen.

CMYK stands for ‘cyan, magenta, yellow, key (black)’ these are the colours used on the metal plates when documents are printed. Be it either in a professional printers or on your home printers. Everything printed uses CMYK colours to print. Because print colours consist of using cyan, magenta, yellow and black, images formatted in CMYK will be of vibrant quality when printed compared to if they were formatted in RGB.

RGB stands for red, green and blue. These colours are used on anything screen like computers, phones, ipads etc… they will all use the colours RGB. Because screen colours make colours using red, green and blue, images formatted in RGB will be of vibrant, brilliant quality, compared to if they were formatted in CMYK.

Hi Res vs Low Res – High Res and Low Res stands for high and low resolution. images are formatted as high and low res. But what makes an image high and low res?

Well, images are made up of tiny little dots we call pixels, the more pixels an image uses the higher quality and the bigger the size. A hi res image is any image 300 dpi (dots/pixels per inch) or higher. These hi res images are high quality images and are needed for print. Print images need to be of high quality as actual ink is been used to print, and with spread and absorption ect… images can loose some quality and become dull looking or fuzzy. So by making images hi res for print you counter round this problem of loss of quality.

Low res images are used for screen and usually have a minimum size of 72dpi. They can be more, but you have to take into consideration screen images take time to load on the internet and on peoples electronic devices, so saving at a low size is optimal for web as people will not be waiting ages for pages to load and open. And if you have a lot of images on a web page at hi res, then you will be waiting a long time for loading and could potentially end up loosing custom. People are impatient, no-one wants to wait around for a page to load, the internet has to be fast, quick and easy. Also because these images are not physically getting printed with ink, they do not loose any quality on screen with low resolution.

Conclusion… – CMYK and Hi Res = For Print      

                            – RGB and Low Res = For Screen

Okay… Now I have gone over the main difference in formats for print and screen, I will now go into some of the main file types and how and where they should be used. There are many different file types out there (but for the sake of both our sanities by getting too technical) I will just go over the main ones people will come into contact with and where they should be used, in a handy little chart thing. 🙂

Screen n Print

Different file formats can be confusing and goobledy goope for people. But I hope with this quick and handy guide of where and why they should be used, will help people get a better understanding on some of them and will hopefully aid in future to their file decisions and which ones to use. 🙂

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