So you’ve decided you’d like to print a particular digital image but you aren’t sure about the size at which you can print it at whilst maintaining a suitable resolution [sharpness]. This is a common question we get asked by our customers and in truth there is not really a one-size fits all answer because there are a number of variables at play. These mostly include:
- What is your personal tolerance for flaws.
- At what distance will you be viewing the work from.
- The cost associated with the printing itself and any subsequent additional costs such as framing.
In this article we’ll try to provide some guideline information to consider but we’d encourage you to get in touch if you need further help. We’ve also created a free tool that allows you to upload your image to check its size and resolution, but if this is all totally new to you, it might be best to read on first.
What defines a high resolution image?
Let’s kick things off by discussing what defines a high resolution image. This is basically an image that will result in the best possible print output with excellent sharpness and detail at the desired size.
When it comes to printing, a high resolution image would be defined as an image that is at least 300 PPI, or “pixels per inch”. You may also hear printers specifically talking about DPI, or “dots per inch” but for the sake of trying to keep this article more customer friendly, let’s stick to PPI.
Pixels are individual dots of colour that make up your on-screen image. The PPI of an image is the quantity or density of pixels contained within one square inch of your image. A high PPI of 300 will produce a clearer image than a PPI of 72 simply because there is more pixels per square inch.
How can I check the resolution of my image?
There are many ways to check the size of your digital images, but here is some quick options on MAC and PC devices:
Using a MAC: right click on the image and then click “Get Info”. In the dialogue box that pops up, look for “Dimensions” and you’ll find your image size in pixels.
Using a PC: right click on the image and then click “Properties”. In the resulting dialogue box, click on the “Details” tab and you’ll find dimensions in pixels and resolution information.
If you have an image editing application such as Adobe Photoshop you can quickly check by selecting Image -> Image Size.
Once you know the pixel count of your file [the height & width] you can calculate how big the file can print at whilst hitting 300 PPI. Let’s use a working example to walk through the calculation involved.
In this example we have an image downloaded from a popular image repository called Unsplash. The original image size is 5184 x 7752 pixels and currently its set to 72 PPI which is the usual resolution of images used on the web. If we printed this image at the existing 5184 x 7752 pixels [which is 72″ x 107.6″ for reference] it would have some pixelation, softness and blurriness as a result of only being 72 PPI. In general our advice in this example would be to reduce the image size to improve output quality.
So how do we calculate the maximum print size of this particular image to get to 300 PPI? We just take each of the height and width in pixels and divide them by 300:
5184 divided by 300 = 17.28″
7752 divided by 300 = 25.84″
Therefore the maximum print size of this file at 300 PPI would be 17.28″ x 25.84″. In Photoshop we can also figure this out by unchecking “Resample” and altering the width and height in inches until such point the resolution hits the desired level, in this case 300 PPI.
Can I print lower than 300 PPI?
Absolutely. You can consider 300 PPI as the gold standard, which means print files around 150 – 200 PPI are still more than likely going to produce good results in most situations. If printing with us we’ll always review your files and discuss any challenges with regards resolution before proceeding.
One thing that is worth noting here is your intended print size and viewing distance. As a general rule of thumb, the larger your print size, the lower the PPI value you may be able to get away with. This is because people typically view a larger print from further away and thus the fine details which may be missed by a lower resolution print will not be particularly evident any way. We have printed a lot of lower resolution images simply because the size of the print file and the viewing distance ensured that the end outcome was actually acceptable to the client.
For smaller prints where you may have a shorter viewing distance, the need for 300 PPI may be more necessary to ensure appropriate detail is captured.
Can you enlarge my image and resolution?
Yes, in many cases we may be able to enlarge your original image and use various techniques and software to create a larger version of your original. You can check out our services page on image enhancement for more details on how we can help or just get in touch.
