Quality and image resolution are two essential things to consider when it comes to editing photos and creative assets. If your images are going to be printed, more specifically, you’ll also need to understand how DPI can affect your project.
Whether you’re new to photography and design or just revising your knowledge, read on to learn what DPI is and how it applies to your digital images.
DPI or “dots per inch” is a way of measuring an image’s original intended size and its resolution, or quality. DPI is a measurement of dots per inch of a printed or monitor-viewed image. The higher the dpi, the higher the resolution, and the better the image quality. Most stock photo agencies offer stock photos to buy from 72 dpi to 300 dpi. We recommend buying the highest resolution you can get. You can always change the DPI from 300 dpi to 72 dpi in any common image editing software like Photoshop.
When it comes to printing, understanding dpi (dots per inch) is essential. DPI can determine the quality of your prints as well as how large or small an image will appear on paper or other materials. But what exactly does dpi mean and how do you calculate it? This article provides a comprehensive guide to help you understand what is DPI and give tips for choosing the right resolution for your project. We’ll also provide a table of commonly used resolutions so that you have all the information at hand when selecting images with optimal size and clarity!
1. What is DPI?
DPI stands for Dots Per Inch and is a measure of the resolution of an image. It refers to the number of individual dots that can be placed in a line within the span of one inch.
If an image was a mosaic, the dots per inch would be the tiles. So the higher the DPI, the more detail and clarity will be present in an image. For example, if you have two images with different resolutions – one at 72 dpi and another at 300 dpi – then the 300 dpi image will appear much sharper than its lower-resolution counterpart due to its increased level of detail.
Definition of DPI
DPI is used as a measurement for printing purposes and digital media such as web graphics or mobile devices.
When it comes to printing, higher DPI means better quality prints since each dot contains more information about color and shape, resulting in smoother gradients and sharper details when printed on paper or other materials.
Digital media also benefit from high-resolution images since they appear clearer on screens than low-resolution ones.
How Does DPI Affect Image Quality?
The amount of detail contained within an image depends heavily on its resolution (measured by pixels per inch or PPI) and its size (measured in inches). Higher resolution images contain more data which translates into greater levels of sharpness and clarity when viewed up close or zoomed in digitally; however, this increase in detail comes at a cost since larger files take longer to download or transfer over networks compared to smaller ones with lower resolutions. Additionally, some output devices may not support very high resolutions, so it’s important to consider your target audience before choosing your desired resolution for any given project.
What is the Difference Between PPI and DPI?
PPI and DPI are measures used to determine how much image data is contained within one inch. PPI stands for Pixels Per Inch, while DPI stands for Dot Per Inch.
There is a subtle difference between them – PPI measures how many pixels are displayed per inch, whereas DPI measures how many physical dots make up those same pixels when printed on paper or other material surfaces such as fabric or canvas.
This distinction becomes especially important when dealing with large format prints, as even small changes can drastically affect print quality; it is best practice to always use appropriate measurements depending on the type of output device being used (e.g., printer vs monitor).
2. Commonly Used DPI Resolutions
Low Resolution (72 dpi):
Low resolution is the lowest quality image setting and is typically used for web images or other digital applications. It produces a low-quality, pixelated image that will not look good when printed. For example, an 8×10 inch photo at 72 dpi would have a total of 576 x 720 pixels which would result in a very grainy looking print.
Medium Resolution (150 dpi):
Medium resolution is often used for printing photos on standard home printers or for viewing on computer monitors. This setting provides enough detail to produce decent prints but may lack sharpness and clarity compared to higher resolutions. An 8×10 inch photo at 150 dpi would have 1,200 x 1,500 pixels which should provide acceptable results when printed from most home printers.
High Resolution (300 dpi):
High resolution is considered the industry standard for professional printing and offers superior quality with more detail than lower resolutions can provide. An 8×10 inch photo at 300 dpi has 2,400 x 3,000 pixels which should be sufficient to create clear prints with crisp details even when enlarged significantly.
Very high-resolution settings are generally only necessary if you plan to enlarge your photos significantly or require extremely detailed prints such as those needed for large-format posters or billboards. An 8×10 inch photo at 600dpi has 4,800 x 6,000 pixels which will produce incredibly sharp prints even when enlarged multiple times over its original size without losing any detail or clarity in the process.
3. Finding the DPI resolution of an image?
Finding the DPI resolution of an image is straightforward when you use Adobe Photoshop. Photoshop measures resolution in PPI, but its ratio of PPI to DPI is 1:1, so you can still find out what the DPI of an image is.
Just follow these simple steps:
- Launch Photoshop on your laptop or computer.
- Navigate to File > Open and select your image.
- With your image open, click Image > Image Size.
- Select Pixels/Inch in the drop-down box besides Resolution. This will give you the resolution value.
How to find the DPI resolution in InDesign.
You can also find the DPI resolution of an image using Adobe InDesign. InDesign is professional page design software, perfect for editing and designing posters, magazines, prints and banners.
InDesign uses two terms to refer to resolution — Actual PPI and Effective PPI.
Actual PPI is the resolution of the image while at 100% of its original size, meaning when the image is at its original dimensions without being resized.
When you enlarge an image, the existing pixels are stretched to accommodate the new size. This is where Effective PPI comes in. This refers to the resolution of the image based on how it is placed on the InDesign page — showing how the final product would look if it was enlarged or reduced in size.
So, for instance, if you wanted to print an image at 300 DPI, you would need to make sure the image has an Effective PPI of 300.
Here are step-by-step instructions of how to do this on InDesign:
- Launch InDesign on your laptop or computer.
- Navigate to File > New > Document and select OK when you are happy with the page dimensions.
- To insert an image, select File > Place, then choose your image file by clicking Open.
- Click to place the image anywhere on the document.
- To find the resolution, navigate to the top bar and select Window > Links.
- This box will give you your image Dimensions, Actual PPI and Effective PPI. If you can’t see this information, expand the box using the Show/Hide triangle (>) to drop it down.
How to find the DPI resolution on Windows.
You can also find the DPI of an image on Windows. Just follow these steps:
- Open File Explorer and navigate to your image.
- Right-click on the image file and select Properties.
- Click the Details tab at the top bar.
- Scroll down to find image Dimensions and the DPI Resolution.
How to find the DPI resolution on Mac.
To find the DPI resolution of an image on Mac, you need to use Preview, the default app.
- Open Finder and navigate to your image.
- Right-click or control-click the file and select Open With > Preview.
- With Preview open, go to Tools > Show Inspector.
- Select General Info from the dialog box, this should be the first tab at the top.
- View the image information to find the resolution or click More Info in the second tab at the top to find the DPI.
How to change DPI on Photoshop.
It’s easy to change and customize DPI resolution using Photoshop. Just follow these instructions:
- Launch Adobe Photoshop on your laptop or computer.
- Navigate to File > Open and select your image.
- With your image open, click Image > Image Size.
- Here, you can adjust the Resolution, Image Size in Width and Height and Dimensions to your liking.
If you don’t want to change the pixel dimensions of your image, make sure to deselect Resample while you use these tools. Resampling can add additional pixels to your image artificially, which can degrade image quality and make it look worse than before.
- ‘Work backwards’ to find the right DPI for your project, by considering its final purpose. How will it be presented? Will it be viewed from afar? What size does it need to be?
- Check what resolution is required before committing to print. Then, double-check your settings to avoid unwanted surprises and wasting materials.
- Use the highest possible megapixel camera when taking photos. That way, you’ll capture as much data as possible to give you a higher resolution when you come to edit and print them. However, note that >high-resolution images will also have a much larger file size, too.
- Take time to consider the right printer paper and ink type. This can all affect how premium the final product looks and feels. For example, will you need gloss, matte or silk coated paper? Some organizations may even want to use carbon-balanced paper which is more environmentally friendly.
The number one concern about undergoing a printing project is your design not looking exactly how you envision it. If you’re not a design expert, which most of us aren’t, there are some small but very important details that we tend to not only overlook, but misunderstand.
Some of those smaller details you can’t miss when sending in your designs for print, including the bleed, trim, and safe zones. Knowing and understanding these specs will make your prints look their best.
Before we get into the meat of it, let’s clear up why you, as a customer, need to be mindful of providing a printing service with these specs. While our state of the art equipment will deliver the best looking final product, there is still a margin of error with the operation.
Therefore, the machine’s that are used for cutting your materials after printing may not cut your image perfectly. To eliminate this possibility, we recommend that the edge of the background image to your product extend beyond that initial edge.
Now that you understand why it’s important to take these steps on your end to achieve a perfect print job, here’s an easy tutorial on how the bleed, trim and safe zone in printing function, so that your prints never look less than perfect again.
Let’s start with the trim. The trim zone is a technical way to refer to the finished size of a product. For example, a standard 4” x 6” postcard is also its trim size. This means in a layout file, the trim lines show you where the product will be cut down to its desired size.
Why does the trim size matter? Well, as you upload your design, it’s useful to be aware of where your trim edges are so that you may extend your image further than the edge, in order to eliminate any margin or error that is bound to occur when your product gets trimmed.
To establish where, and how much of your image should go beyond the trim edge, is everything that falls over into the bleed zone. The size in which your images should extend into both of these margins will be listed in the next section, the bleed zone.
To make it simple, a bleed is the extra margin on print materials that is meant to be trimmed off when the product is trimmed to its final size. It literally means that the color and graphics on a product will “bleed off the page” so that when your image reaches the edge, it won’t leave any unwanted white edges.
You can set your bleed in a layout file by extending past the trim line to where the blade will cut through. You may be asking yourself why you have to incorporate a bleed zone in the first place.
Giving yourself a bleed zone will help eliminate the inevitable margin of error where the actual cut is made. If you don’t include a bleed, there will be a white border left on the edges.
To know the exact size to extend your artwork with a bleed zone depends on the product you’re printing. For example, most business cards have a 0.1” bleed, meaning a standard 2” x 3.5” sized card will have a bleed size of 2.1” x 3.6”.
See the list below for the correct bleed size for GotPrint products. These sizes should also apply for your trim size.
- 0.1″ bleed: most business cards, folded business cards, bookmarks, CD packages, club flyers, collectors cards, DVD packages, event tickets, most postcards, rack cards, rip business cards, rolodex cards, stickers, table tents, greeting cards, “wink” special shapes.
- 0.125″ bleed: a-frame signs, banners, brochures, door hangers, envelopes, flyers, folded hang tags, hang tags, illumaprint panels, letterheads, mini menus, notepads, posters, posters (wide), roll labels, retractable banner stands, staggered cut flyers, window clings, window decals, yard signs.
- 0.25″ bleed: booklets, calendars, catalogs
- 0.3″ bleed: folders
- 0.325″ bleed: business cards with round corners in either 2” x 3.5” and 3.35” x 2.17” size. Postcards with round corners in the following sizes: 4” x 6”, 5.5” x 8.5”, 4.25” x 5.5”, 5” x 7”. All special shapes, except for “wink” special shape, which is 0.1″.
Now that we’ve covered the hard parts, the last step seems more apparent. However, you still need to be careful about what you put into your safe zone.
The safe zone is the area where all the most important, critical elements (such as text, images, logos, etc) are placed. Making sure they are within the safe zone is the only way to avoid these elements from being trimmed off once the product is trimmed to the final size.
If you extend your text, images, or logos to the very edge, then you are risking those elements being cut off! You must give plenty of room for your safe zone, because even the smallest deviation could result in an uneven finished job. It is often recommended by design experts to allow your images to have at least 5mm-6mm around the edges of your product.
The actual cut can happen anywhere between the bleeds and the safety margins, so it’s important to allow plenty of room for mechanical tolerances. Keep in mind that wider margins help to accommodate more printers while preserving the integrity of your designs.
The diagram below shows you where to keep all of the critical elements you want to go into your print job.