Guide to Image Resolution
29th July 2014

Image Resolution Guide

image-resolution-guide

One of the most common issues when printing is resolution. If low it can make a picture look blurred or it can pixelate. The information below will hopefully explain what resolution is the terms DPI (dots per inch) or PPI (pixels per inch), and try and help you to get through this problematic issue, and achieve a quality print result you will be happy with.

 

1. Basic Explanation of Resolution?

You have no doubt heard yourself say ‘It looks ok on my screen, why won’t it print ok?’ The answer is simply that screens will only view documents at 72dpi, all commercial printers print at 300dpi. Images made up from dots are known as raster images, another file format is called vector files and these are when the image is made up from equations. This means it will never distort, regardless of how big you make the it.
image-resolution

?Unfortunately, showing resolution issues online is not easy, however we have tried out best. Below are two identical bodies of text, one is 72dpi and one is 300dpi and scaled to the same hight. The text on the left is clearly more fuzzy and will print that way.

To really see the difference, we’d recommend downloading the example pdf ‘clicking here’ and printing out a copy to see an effective difference in size and pixel (dot) density.

An example image of 72dpi vs 300dpi resolution comparison. To see the effect much clearer, simply click on the image to download a print ready PDF

The above example clearly shows that the left hand text is distorted at 72dpi and will not print as well as the 300dpi, it will print blurred and pixelated. It is important to note that the resolution of a text or image cannot be increased, it must therefore be created at the correct resolution.

72dpi-300dpi
?If you are not a designer then the quickest and easiest way to check your resolution is to zoom in on your pdf. We recommend zooming in at around 300-400% as this will allow you to see the level of detail that will print. We do not blow up any artwork to print it, but as your screen will only show you an image that is 72-100dpi, zooming in will let you see just how this will look.

A Size Size in mm
(without bleed)
Size in pixels 300dpi
(without bleed)
Size in mm
(with bleed)
Size in pixels 300dpi
(with bleed)
Business Card 85 x 55 mm 1004 .x 650 91 x 61 mm 1075 x 720
DL / Comp Slip 99 x 210 mm 1169 x 2480 105 x 216 mm 1240 x 2551
A6 148 x 105 mm 1748 x 1240 154 x 111 mm 1819 x 1311
A5 210 x 148 mm 2480 x 1748 216 x 154 mm 2551 x 1819
A4 297 x 210 mm 3508 x 2480 303 x 216 mm 3579 x 2551
A3 420 x 297 mm 4961 x 3605 426 x 303 mm 5031 x 3579
A2 594 x 420 mm 7016 x 4961 600 x 426 mm 7087 x 5031
A1 841 x 594 mm 9933 x 7016 847 x 600 mm 10004 x 7087
A0 1189 x 841 mm 14043 x 9933 1195 x 847 mm 14114 x 10004

The table above is based on printing a portrait document at 300 pixels per inch which will give a high quality result. When measuring a digital image there is no defined size in cm or inches, this is determined by the dpi. For example an image that is 1748 x 1240 pixels would be A6 size at 300dpi or A4 size at 150dpi. (An A4 document is twice the height and twice the width of an A6)

3. How to create high resolution documents (or fix documents)?

Once you have used the above rule, click on the following option that applies to your document. Most will fit into one of the below.

If certain parts of the document are low resolution:

Replace
If you have noticed that your images or logos are low resolution, then you are best to replace them. You will need to make sure the replacement files are of a higher resolution or are vector files. Therefore it is always best to search for better images from either your graphic designer or from previously printed documents that have not had this issue. Should you need to purchase any images online from sites such as iStockphoto or Shutterstock, then please make sure you by them at the correct resolution. Our team at Print-Print are happy to advice you if you are unsure.

Re-size
You can sometimes reduce pixelation by simply making your image smaller. Always remember to zoom in on this after to make use you are happy with how it looks.

Rebuild
This is the more expensive option as pictures cannot usually be recreated. However if it is a logo that you need rebuilding, this can be done by a designer. If you do not have on to hand then we are more than happy to help. Simply call us for a quote.

Risk it
This is not our favourite option. However if you are not able to do any of the above and are happy with how the images look when you zoom in, we will proceed with print.
Part of the document is vectored and the rest is low resolution.?
This usually suggests your software settings are incorrect and are causing a drop in quality when you save your document out. Some frequent cases of these issues occur when saving a word document straight to pdf, or having incorrect export settings on an Indesign document.

?Solving this problem can be quite simple, all you need to do is change the options you are offered when saving your document. Resolution options should be set to 300dpi minimum and, if you have compression options, these should be set to the maximum options. Please see the bottom of this guide for screen shots of where these options can be found. Once this has been done, re-save and then zoom in. If you are now finding only certain bits of your document are low resolution, then please go to the options above.

Can we improve the resolution of my design??

?The simple answer is no. It is not possible to improve the resolution unless you use the original document.

I can’t improve the resolution of my design what can I do?

?As briefly mentioned above, you have two main options. These are to either have have our document recreated by a graphic designer, or we can print it as it is. You will need to remember that low resolution documents will not print to a high quality as mentioned above.

 

Can Print-Print help?

get in touch and we can see if we can best advice you on which course of action to take
Call us on 01952 850730 or email us at hello@print-print.co.uk.

 

About Danny Molt

Danny Molt is an all round follower of great design working for Print-Print Limited, promoting business and building your brand through quality printing. If you're passionate about small business marketing then please get in touch info@print-print.co.uk