The quality or “resolution” of the images is important – if it’s too low, your pictures look blurry or be pixelated.
If it’s too high, your file may be too large to upload or take too long or a lot of bandwidth to download.
For best results, it is recommended that images are a minimum of 240dpi but no more than 300dpi.
- To get the best quality, start off with the largest scanned or downloaded version you can
- Check your image at 100% on screen to get a good idea of how images will look when printed.
- If they look clear on the screen they should be clear in print
DPI mean Dots Per Inch, which is the amount of dots per inch of resolution in an image. A higher number of DPI will translate into a larger image file size.
300 DPI is the standard minimum for printing an image on an offset printing press.
72 DPI is the standard for a web image, although that is changing with higher resolution screens such as Apple’s iphone retina displays.
WHAT IS IMAGE RESOLUTION?
The number of pixels per inch in a picture is know as its resolution (or ‘res’ for short). If you zoom into any picture on your computer screen, you can see that it’s made up of pixels (small squares). The higher the number of pixels, the higher the dots-per-inch (aka dpi or resolution)
Low-res images can look blocky, pixelated or blurry on screen and in print, like this:
Whenever you make a picture bigger, you reduce the resolution. The pixels in the picture have to be stretched over a larger area, so if you start off with a picture at 150dpi and you make the picture twice as big, it will end up as 75dpi (half the resolution).
If you want to have a large picture in your newspaper, you need to start off with a higher resolution image. For example, if you start off with a 300dpi image, and enlarge it to twice its size, the resolution will be halved to 150dpi – which is fine for newspaper printing.
Lots of scanners give you the option to scan at 75dpi, 150dpi, 300dpi, 600dpi or higher. This means you can scan a fairly small picture (maybe an old photograph) and enlarge it, without the resolution going below 150dpi.
If you scan in at 300dpi, you can enlarge the image to twice the size and it will still be 150dpi, enough for newspaper printing. If you want to enlarge your picture more, scan at a higher resolution, for example 600dpi.
USING PICTURES FROM THE INTERNET
Pictures on websites are usually low-res (around 72dpi) as this helps a web page to load more quickly. If you try to enlarge a small image taken from the internet, you can quickly end up with a very low-res image, which won’t look good in print. If you do want to use pictures from the internet, try to find the largest versions you can. Once you’ve put your newspaper together, you can check how the pictures look by viewing your PDF at 100% on screen. This gives a good indication of how things will look in print. Our online checker will also pick up any low-res images when you upload a file for printing.
We don’t recommend saving text as an image file (eg JPEG or GIF) as it won’t print as clearly as text rendered in ARTHR.
If you do want to save text as an image file, or if you have maps, or diagrams that are JPEGs, GIFs etc, it’s really important that you save them at the highest quality you can, so that the text is readable. If saving as a JPEG, make sure that you put the quality up to 100%, and remember, if you enlarge an image you’re going to reduce the dpi (quality) and the readability of the text.
Text saved as a low res JPEG, GIF etc will look blurry or pixelated in print:
If you save text as a JPEG, it can appear with a ‘halo’ around it, and look a little fuzzy. Again, make sure you save it at the highest quality to reduce this effect.