What is DPI? An Essential Guide for Designers

To achieve superior print quality, it's crucial to comprehend what DPI (Dots Per Inch) represents and its critical role in image resolution. Whether you're a photographer, graphic designer, or an individual seeking high-quality prints, understanding the importance of DPI can significantly impact your results. This article delves into the meaning of DPI and its significance in print and digital media. It guides adjusting DPI settings using renowned software like Adobe Photoshop and InDesign. By the conclusion, you'll clearly grasp how DPI resolution influences the visual clarity and intricate details of your printed works, empowering you to craft captivating and professional-grade prints with absolute assurance.

Before reading on, be sure to understand how pixels work for photographs and other printing methods. 

What is DPI?

What is DPI? DPI stands for Dots Per Inch, representing the number of printed dots within every inch of a printed document, or every 2.5cm.

Why does DPI matter? Well, the greater the DPI, the better and more precise the end product. A higher DPI typically ensures a higher-quality print because it provides more information to the printer, allowing it to recreate images with sharper detail.

So, what does DPI mean for your prints? It stands for a crucial factor in determining print quality. A lower DPI is okay, as we'll touch on it shortly. However, it can often lead to pixelated items as the machinery produces blurred and disappointing designs.

Make sure to learn about PVC banner printing when learning about DPI too. 

Guidelines

What is DPI? DPI stands for Dots Per Inch, which defines the number of dots within each inch of a printed document, also known as DPI resolution.

If you're unfamiliar with DPI, always aim for higher values to ensure better print quality. However, some rough guidelines influence your artwork decisions.

Low Resolution refers to anything set to 150 dpi or less, and it's strongly advised to avoid this for any printing, regardless of the project.

Medium Resolution, ranging between 200 and 300 dpi, is much more acceptable and popular for smaller projects like marketing collateral, leaflets, and brochures. While 300 dpi is considered a minimum for such materials, standard photos for home printers typically fall within this range.

On the other hand, High Resolution is defined as anything set at 600 dpi or more. Achieving such detail is beyond the capabilities of most desktop printers, making professional printers essential for obtaining high-resolution prints.

Giant advertisements are often printed at 1200 dpi, highlighting the significant difference in scope and quality between various resolutions.

While it's true that smaller designs may not necessarily require high DPI, it's generally better to err on the side of higher DPI values to preserve image quality. Scaling down images is possible, but attempting to scale up low-resolution photos will lose quality.

From our perspective, receiving artwork saved in low Resolution is frustrating, as it becomes challenging to work with such files. Therefore, it's crucial to be mindful of DPI settings when preparing artwork for printing.

Deciding Factors

With your design, it's essential to address three fundamental questions:

• Where will the procedure be placed?
• At what size will it be printed?
• What material will be used for printing?

Design experts advise considering the viewing distance as a crucial factor. Interestingly, a high DPI is less critical for larger displays like billboards. Since billboards are intended to be seen from a distance, a lower DPI is often sufficient, ranging from 20 to 50 dpi. Surprising.

However, it's important to note that DPI should not be confused with the actual size of an image; pixel density is separate from dimensions. Altering the size of a digital design can suddenly impact its Resolution, leading to a reduction in quality.

As a helpful rule of thumb, scaling up the size while reducing the Resolution helps maintain better quality at that level. For instance, doubling the width and height of an image when halving the Resolution can preserve its overall quality.

The chosen print material also plays a significant role as different substrates retain detail to varying extents. For everyday print work on uncoated paper, a 200-250 dpi resolution is more than acceptable. However, glossy materials hold detail better and may expose any lacking resolution.

In summary, considering the viewing distance, printing size, and material type will guide you in determining the most suitable DPI for your design, ensuring it achieves the desired quality and clarity.

Check out our go-to products for waterproof outdoor poster printing. 

What’s DPI used for?

DPI, which stands for Dots Per Inch, is a crucial measurement for printer resolution, determining the clarity and detail of an image on paper. It plays a significant role for photographers and designers, directly impacting the quality of printed assets, whether a poster, a brochure, or a glossy magazine.

DPI is what ensures an image looks crisp and high-quality. A higher DPI number indicates that ink droplets are tightly bunched, resulting in finer detail and smoother prints.

It's not just printers; scanners also utilize DPI to gauge image quality. The DPI value represents the number of data points the scanner and computer capture from the image.

It's important to note that DPI can vary depending on the type of printer. Standard inkjet or laser printers can produce images at a minimum of 300 DPI or even higher. On the other hand, professional-grade printers may require printing photos with a resolution twice that number to achieve the desired level of quality.

What is 300 dpi?

An image with a resolution of 300 DPI signifies 300 dots of ink packed into each inch. 300 DPI is a standard benchmark for printing top-notch images for photographers and graphic designers. Nonetheless, larger images might necessitate an even higher resolution to ensure optimum print quality.

PPI

DPI stands for Dots Per Inch, representing the number of round printed dots within a square inch of a printed image. On the other hand, PPI refers to the number of square dots displayed on a computer monitor before any printing occurs.

Converting PPI to DPI is a straightforward process when saving artwork for print. For example, changing 2000PPI to 2000DPI can be done with little hassle. However, a word of caution when dealing with desktops and laptops – these screens often adjust images to suit the end user, making designs appear larger than they are. High-performance computers with better screen resolutions are recommended to get a more accurate representation of sharpness.

Popular photo editing programs like Photoshop offer easy options to adjust PPI that can be tweaked in seconds. It's a simple and efficient way to manage image resolutions for different purposes.

How does DPI differ from PPI?

PPI (Pixels per Inch) represents the number of pixels within each inch of a digital image, specifically describing image resolution on a screen rather than in print. On the other hand, DPI refers to the number of dots within each inch and is primarily utilised for print purposes.

Despite their distinct applications, PPI and DPI serve similar purposes by indicating the overall Resolution of an asset. This similarity often needs to be clarified between PPI and DPI resolution.

How do I find the DPI resolution of an image?

An image's DPI resolution becomes an effortless task with Adobe Photoshop. Although Photoshop measures resolution in PPI, the PPI-to-DPI ratio is 1:1, allowing you to uncover the DPI of an image. Here's a straightforward guide to follow:

• Open Photoshop on your device.
• File > select the image you want to use.
• Select Image > Image Size.
• Click on resolution, click Pixels (Inch). This will show the resolution value, which parallels the DPI of image.

How to find the DPI resolution in InDesign.

You can also determine the DPI resolution of an image using Adobe InDesign, a professional page design software ideal for editing and creating posters, magazines, prints, and banners.

InDesign uses two terms to describe Resolution — Actual PPI and Effective PPI.

Actual PPI represents the image's Resolution at 100% of its original size, meaning when the image is displayed without any resizing. On the other hand, Effective PPI comes into play when you enlarge a picture, as the existing pixels are stretched to fit the new dimensions. This term refers to the Resolution of the image based on how it is placed on the InDesign page, showing the final appearance if the image were to be resized.

To achieve a specific print resolution, like 300 DPI, you must ensure the image has an Effective PPI of 300.

Here's a step-by-step guide on how to find the Resolution using InDesign:

• Launch InDesign on your device.
• Open a new document and select 'OK' once you're satisfied with the page dimensions.
• To include an image, click File > Place, and choose the image file by clicking 'open.'
• Place the image anywhere in the document. 
• To find the image resolution, use the top bar navigation and choose Window > Links.
• This box will allow you to check image dimensions, PPI, and effective PPI.
• If you can't access this data, widen the box with the Show/Hide triangle (>) icon to reveal it.

Finding the DPI resolution using Windows.

You can easily find the DPI of an image on Windows by following these simple steps:

1. Launch File Explorer and find the image you wish to use.
2. Press right-click to view the image properties.
3. Check the 'details' tab at the top.
4. You can find the image dimensions and DPI resolution at the bottom. 

Finding the DPI resolution using Mac.

To determine the DPI resolution of an image on Mac, you can utilise 'Preview', the default application for viewing images. Follow these straightforward steps:

1. Find the image using 'Finder.'
2. Rich-click on the image, choose open with, and hit 'preview.' 
3. After opening 'preview,' go to the 'tools' option and select - 'Show Inspector.'
4. Click on 'general info,' (the first tab at the top).
5. To find the resolution, view the image information. Alternatively, you can click on More Info in the second tab at the top to discover the DPI.

What DPI should I use?

What is DPI, and what does DPI stand for? DPI stands for Dots Per Inch, which refers to the number of ink dots in each inch of a printed image, determining its Resolution.

So, what does DPI mean for your images and how to choose the correct DPI resolution?

The appropriate DPI will depend on your desired outcome and purpose. When deciding on the DPI to use, consider the following factors:

• Size: Larger images intended for printing require higher dot density (DPI) to maintain high-quality appearance. A higher DPI allows you to scale up the image without compromising its quality.

• Viewing Distance: The distance between the viewer and the printed image affects the required resolution. For posters and certain art prints viewed from a distance, you may need lower DPI to still achieve a satisfactory level of detail.
• Paper, Printer, and Ink: The type of printer and materials used can also influence the image's sharpness when printed.

For most photographs, flyers, or business documents, a general benchmark for achieving high-quality prints is 300 DPI.

If you're creating a poster, the required DPI depends on the size and viewing distance. Typically, a minimum of 100 DPI is acceptable. Still, you can experiment with lower DPIs for smaller images or test prints using software like Photoshop, Illustrator, or InDesign to find the best result.

For more professional magazine images or exhibition-quality artwork, you may need 600 DPI or higher to achieve pristine results.

Suppose you are still determining the DPI resolution, especially when working for a client or organisation. In that case, it's always advisable to confirm the DPI resolution they require to meet their expectations and ensure a successful outcome.

To truly understand the scope of DPI, learn how to create a poster with it.

How to change DPI on Photoshop

Customising DPI resolution in Photoshop is a straightforward process. Follow these step-by-step instructions:

1. Open Adobe Photoshop on your laptop or computer.
2. Go to File > Open and choose the image you want to modify.
3. Once your image is open, click on Image > Image Size.
4. In this window, you can make adjustments to the Resolution, Image Size (Width and Height), and Dimensions according to your preferences.
5. If you wish to maintain the pixel dimensions of your image and only change the DPI resolution, ensure to deselect Resample while using these tools. Resampling can artificially add pixels to your image, potentially degrading its quality and making it look worse than before.

Check out our latest article on Paperback vs Hardcover books.

Final Thoughts on DPI

Understanding DPI (Dots Per Inch) and its significance in image resolution is crucial for achieving high-quality prints. DPI is vital in determining the clarity and detail of printed documents, posters, and artworks. While higher DPI values are generally preferred for better print quality, the appropriate DPI may vary based on the specific project, viewing distance, and printing materials. Tools like Adobe Photoshop and InDesign offer easy ways to adjust DPI resolution and customise images to suit various printing requirements. By considering factors such as size, viewing distance, and output type, designers and photographers can optimise DPI settings to produce exceptional results. Ultimately, being mindful of DPI resolution empowers creators to deliver visually captivating and professional-grade prints that meet or exceed the expectations of clients and audiences alike.

Follow our complete guide to printing paper sizes so that you know what to print your DPI on. 

FAQs

Why is DPI important in printing?

DPI is crucial in printing as it affects the clarity, sharpness, and detail of the printed output. A higher DPI generally results in a more detailed and higher-quality print.

What is the standard DPI for printing?

The standard DPI for printing varies depending on the type of output and the desired quality. Commonly used DPI values range from 300 DPI (for high-quality prints) to 72 DPI (for web graphics).

Can I change the DPI of an image?

Yes, you can change the DPI of an image using image editing software. However, it's important to note that simply changing the DPI without altering the resolution won't affect the actual quality or detail of the image.

Does DPI affect image file size?

No, DPI does not directly impact the file size of an image. The file size is primarily determined by the image's resolution, colour depth, and compression method used.

What DPI should I use for web graphics?

For web graphics, a DPI of 72 is commonly used. However, it's essential to understand that web graphics are typically displayed based on the pixel dimensions rather than the DPI setting.

Is higher DPI always better?

Not necessarily. While higher DPI can result in more detailed prints, the benefits may not be noticeable if the viewing distance is far or the original image resolution is low. It's important to consider the intended use and viewing conditions when determining the appropriate DPI.

Sources

Davolt, S., (2023) Pixels to Inches Converter: DPI, PPI, Inch, PX, Centimeters. Blitzresults. [online] Available at: https://www.blitzresults.com/en/pixel/ [accessed 26/07/23]