When creating a print that you want to be of photo quality, it is vital to have the correct resolution size. The general rule is to assume a 300 dpi resolution size.
Pixel dimensions and digital image resolution are related but not similar. Resolution is what determines the sharpness of a print.
Color Accuracy
The color of an image depends on the device used to display it and whether or not it’s properly calibrated. Flat screens tend to produce less accurate colors than print devices, especially if they’re backlit. Luckily, calibration tools help eliminate some of this discrepancy.
Resolution is often referenced in terms of PPI, but it’s important to remember that this measurement only applies to digital images. A print does not have a PPI because it’s not made up of pixels. Instead, a print comprises ink droplets that combine to create a picture.
For this reason, the printing industry uses a different resolution measurement called DPI, or dots per inch. For the most part, you’ll want to stick with 300 DPI for your prints, but some products (like mugs and personalized phone cases) may require higher resolution.
DPI is determined by dividing the size of an image by the resolution size in inches. The smaller the print, the lower the DPI. For the most part, our print team recommends 300 DPI for your posters as it balances print quality and file size.
Brightness
The higher the resolution of an image, the sharper and more detailed it will be. This is measured in dots per inch (dpi). A lower dpi will look blocky and pixelated with little detail. A higher dpi will be more transparent with more delicate details like leaves on a tree or tufts of fur.
Resolution isn’t the only factor determining print quality; brightness also plays a role. Images printed with a high dpi can look very bright, especially when viewed in bright ambient light.
If you’re working on an overly bright monitor, your prints may need more light. Using a display profiler/calibrator to set your monitor luminance consistent with your final medium’s expected ambient lighting conditions is best.
Poster printing services are calibrated to ensure that all color values are represented as accurately as possible on our range of papers. This means that if your print is too dark, it is likely not a paper or printing issue. It is likely an editing/preparation issue.
Resolution
Many people have experienced printing a resized image only to end up with a poster that appears blurry, blocky, and pixelated colors. This is often due to the original image file resolution needing to be higher.
The resolution of an image is measured in dots per inch (DPI). The higher the DPI, the better the print quality will be.
Photo resolution is essential for posters because the prints can be viewed from a great distance, and high-resolution images allow viewers to see details in the image, such as individual leaves or tufts of fur.
The recommended resolution for photo prints is 300 dpi. This is based on the print size and the viewer’s proximity to the image. A shallow resolution would look blocky because your mind couldn’t blend the tiny dots into a picture. For example, imagine looking at a 4×8-inch photo print of a Manhattan skyline from 20 feet away and then zooming in to examine the image closely. You would notice that the pixels are evident at the close view and pixelated at the distant view.
Contrast
Image resolution refers to the number of dots (or pixels) printed in a given area. This information is often measured in PPI or pixels per inch.
Digital images comprise thousands of tiny pixels that blend to create a lifelike image from a certain distance. When looking at a print from about 20 feet away, it is tough to discern the difference between a photo printed at 300ppi and one printed at 75ppi.
The general rule of thumb for the best print quality is to use an original file with a resolution that is 300 ppi when it is 25% larger than the final output size (so if you are printing a 24 x 36 poster, your original file should be 6 x 9 at 300 dpi). This guideline will apply to photographs and bitmaps; designs with text must have a minimum of 150 ppi. Also, note that resizing an image will lower the resolution, so it’s essential to set up your files at the proper resolution in the first place.
White Balance
Resolution refers to the density of tiny visual blocks in a printed image, or dots per inch (PPI). For example, a print made at 72 ppi would appear blurry when viewed from a close distance.
Interestingly, digital images don’t have a PPI because they aren’t made of pixels. Instead, they are made of thousands of invisible lines that blend to create a lifelike image. The same is true of photographs that are scanned or snapped with cameras.
For the best quality, it is recommended that images are used at a resolution of 300 dpi or higher.
To determine the resolution of an image, open it in your photo editing software and look at its pixel dimensions. This number will tell you how large your image can be printed and still be of good quality. Then divide this number by 300 (for an image without text) or 400 dpi (if it contains text). This will give you the maximum usable size of your file.