Resolution

This one always seems to have the last thought when producing print. It's most likely down to the computers we work on as to why it's sometimes forgetton. Resolution is a very important part of printing and without a hi res image or text sometimes your item will look pixelated or fuzzy.

Resolution is usually measured in dots per inch (dpi) or pixels per inch (ppi). Here's where we get relative.
Your computer displays at 72dpi. So for every inch of screen you have there are 72 dots of colour. This was thought to be the best setting for displaying images on Computers, Mobile Phones & TV screens.
In print we need a minimum of 300 of those dots to create a sharp image. Lets take a quick look at a few pictures.
 Here's an image at 72dpi - we've imported it into an A4 landscape document... great it fits... NO! remember I said it was 72dpi so although it looks great on screen, If we're printing this litho or digital - we need a minimum of 300dpi.. So have a look at the below picture - the size of the picture at 300dpi is much smaller. Something you always have to watch out for when using images.

 So you have a picture that you really want to use - but are unsure of the resolution, what can you do. Well taking your image into your layout program will usually then tell you at what resolution you have, or an alternative is to check it's properties for resolutions information. If your image is smaller than the document you've created you'll either have to stop using it - or you could resample it. Resampling is when your image program replaces missing pixels with combinations of surrounding pixels - this method is just a calculation the program runs so will never replace actually shooting the image at the required resolution to begin with.

Remember though - there are some print methods that require lower resolution - for example large format print that is intended to be viewed from a distance is usually lower in resolution than a brochure (which is intended to be viewed at a close range). So make sure you check with your printer what resolution they need from your artwork prior to sending it over.