By Vince Williams
August 10, 2011
Fuzzy images can turn a high-quality communication tool into a distraction that affects your credibility with both your congregation and new attendees. A low-quality image cannot be fixed and can cause delays in otherwise simple projects. Understanding image quality before you create a document is the easiest way to protect your resources from looking unprofessional.
Why would one image look so big and clear on the screen and yet not be useable at half the size on a brochure? The answer comes in understanding pixels and resolution.
Many church communicators (and business professionals alike) are confused by the terms surrounding image quality. They have been told that their print files need to be at 300 dpi, or dots per inch, to look good printed. But what does that actually mean and why do other people use the term pixels? Are pixels also dots and if so how does it all translate? The confusion over these various terms is easy to understand since these words are a collision of two languages, print and digital media. The printing world talks in dots (the smallest amount of ink that can be laid down at one burst), while the computers of the world work in pixels (the smallest element in a digital display, such as your monitor). Dots are physical and pixels are digital.
Let’s take a look at some of the terms related to images:
Pixel. The pixel is the smallest screen element in a digital display. The pixel is a coordinate on a screen mixed with various color information. With each pixel having access to a wealth of color options it can start to form the images we see on the screen. Put another way, a pixel is the smallest controllable element on a display screen.
Dots. Dots represent the smallest amount of ink that a print device can place on a substrate, such as paper or vinyl.
Dots per inch(dpi) or pixels per inch(ppi): This measurement refers to the density of the dot pattern. 100 dpi refers to a printer’s ability to fit 100 dots into an inch of printing. The term PPI simply refers to digital products like monitor resolution.
Resolution. You will hear the word resolution used in various ways. Generally there are two meanings for resolution. The first is “spatial” resolution. This phrase means the same thing as DPI or PPI. It represents the number of base units that can be fit into a given area. You will often hear designers and printers use the term resolution in this way, such as, “The resolution is 72 dpi.”
The second meaning of the word is pixel resolution. Pixel resolution describes the number of pixels that an image holds. Pixel resolution is determined in a grid format where the first number represents the number of pixel columns (width) while the second equals the number of pixel rows (height). A resolution of 1×1 would encompass a single pixel; while 1024 x 768 (a popular monitor resolution) would mean that you had an image that was 1024 pixels wide by 768 pixels tall.
Both aspects of resolution make up the key to determining image quality.
Example of resolution and image quality
Let’s demonstrate how resolution is affected by dpi/ppi. If you start with an image that is 1000 x 1000 pixels and a printer prints it at 100 dpi, then the largest it can print without losing image quality is 10″ x 10″. If that same printer printed at 250 dpi, then the image would have to be smaller to maintain image quality. In this case it would end up 4″ x 4″, because more of the pixels would end up in each inch of the image. The higher the dpi, the better the image quality (up to a point), but also the more pixel resolution an image needs to look good at a larger size.
The image shown above is shown at 72 dpi and makes up an image that is a little over 2″ x 3″ on the screen. If we attempted to print the image at the same size at 300 dpi it would like this:
Since computer monitors show images at 72 dpi and most printers print at 300dpi or more, an image that looks good on a screen will only look good very small when printed. The easiest way to ensure that your image sizes are enough to work on your printed products as well as your monitor is to look at pixel resolution. A 300 x 300 image (larger than the size of many images on Google) will only print a 1 inch picture correctly. Here is the math to understanding the correct pixel resolution:
(Size in inches you want the image) x (dpi of printer) = (pixel resolution required for a crisp looking image). If you needed a 6” x 6” image on your bulletin and you were printing at 300dpi it would require a pixel resolution of 1800 x 1800 to give you accurate reproduction without pixilation.
Finding high resolution files means getting your images from better quality stock image sites, non-compressed camera files, or working with an image library like ours. These images are designed for print and can make sure that your printed products look their best.
Understanding image size will help you improve the quality of your church communication. Although our crew at SermonView cannot fix low-resolution images, we can offer our expertise and image library to your print projects. If you have questions about any of our printing or design services, give us a call at (888) 336-3048.