If you’ve ever had a digital image printed, you know how quickly you’re accosted with acronyms and terms never before encountered. What’s worse, you’re expected to understand this jargon so well that you can ensure your organization is getting the highest quality printed product possible!
Below, we’ll explain in plain terms the most common questions about transforming digital images onto real surfaces that we receive every day. Bookmark this article and the next time you need an image printed to perfection you can be confident that you’re providing the precise file so you can get your vision produced.
Before we hash out the particulars regarding what you should know about optimizing a digital image for non-digital printing, we wanted to give a simple glossary of terms used throughout the article. Peruse these and refer to them as you read to get the full ‘picture’ (pun fully intended).
Pixel – A pixel is the smallest physical element of any digital display that the human eye can detect. No matter the size or resolution, an image is always a specified number of pixels.
PPI (Pixels Per Inch) – PPI is the density of pixels on a screen or the density of pixels within a digital image. Adjusting the PPI modifies the physical size and relative quality of a digital image when converted onto a non-digital surface.
DPI (Dots Per Inch) – DPI is the density of dots in a given printed image. Printers reproduce an image by laying out small ‘dots’. These small dots are comprised of the CMYK colors (cyan, magenta, yellow, and black). The colors combine visually to create the particular hue. The space between these dots is what’s measured with DPI.
Resolution – Resolution is the measure, or count, of pixels in a screen or a digital image. Typically resolution is expressed as width x height.
What’s the difference between DPI and PPI?
Both DPI and PPI are used to describe an image’s resolution, but the two aren’t the same. Due to the interchangeable use of DPI and PPI, there remains a cloud of uncertainty regarding the two acronyms. Simply put, DPI refers to the number of dots encompassed within one inch of a printed image, while PPI refers to the number of pixels residing within one inch of an image displayed on a computer screen. Continue reading the questions below for more points of difference.
Who decides the DPI?
It is not actually a person who decides DPI; it is a thing. The printer used to transfer the digital image to a non-digital surface determines an image’s DPI. It is simply a technical aspect of each individual printer a printing company uses.
Who decides an image’s PPI?
This one is a who, and it is the image’s designer who determines PPI. Setting the right PPI is paramount in sending a good digital image to printing.
What does changing PPI do to the image?
Some think that changing PPI changes the quality of an image, but really the PPI you set only dictates the size of an image, not its quality. The ‘absolute’ resolution of an image does not change. In other words, there are still as many pixels in the image regardless of PPI adjustments. The pixels are just scaled up or down depending on your input.
How do you change PPI in Photoshop?
To change your image’s PPI in Adobe Photoshop, simply go to the image, select image size, and then type in the number you want where it says resolution. And if resample is checked, deselect that. Choosing to resample an image keeps its original size and tries to add information to the current image to increase its PPI, which usually produces a pixelated and blurry image.
What does changing the DPI and/or PPI change about the final printed image?
The best way to explain this is an example. Let’s say you have an image with a resolution of 720 x 720 pixels. If you set this image to 72ppi, the image will be 10 x 10 inches and include 72 pixels within every square inch. When that image is printed on a 1200dpi printer, you’re still left with 72 pixels per inch. But, those 72 pixels per inch are comprised of 1200 dots per inch.
How can I tell the non-digital image size from PPI?
Dividing the total number of pixels in the image by the set PPI allows you to find the size of the printed photo in inches. For example, a 600 x 600 pixel image with 10ppi produces an image sized to 30 x 30 inches.
Does increasing PPI increase quality?
Increasing PPI does not mean an increase in quality. To increase quality, resolution needs to be increased. Sometimes the size of the image and its resolution both need to be changed to increase an image’s overall quality.
Does increasing DPI increase quality?
Generally speaking, a higher image DPI supports higher line screens, as well as produces smoother color blending and enhanced image tonality on the printed image. However, as there is no standard dot size or shape, one printer with dots at 1000dpi may look similar to another printer with dots at 500dpi.
What’s the difference between ‘image size’ and ‘file size’?
The image size refers to the dimensions of the image itself. On a printed image, an image size is described by its width and height using inches or centimeters. With digital images on a computer screen, the image size is described by its number of pixels wide and high. File size describes the amount of space an image occupies on your computer, or how much space is needed to store your image on your computer’s hard drive or on your camera’s memory card. The standard measurements of file size are kilobytes (KB), megabytes (MB), and gigabytes (GB), with KB being the smallest and GB being the largest.
At Ferrari Color, we’ve taken the time to thoroughly master the intricacies of every prevalent raster image manipulation program. We’ve done this for one purpose: to make it easier for you and every one of our clients!
Reach out to us and let us help with your next custom graphics project.