Optimizing Raster Image DPI for Print in Affinity Designer on iPad

Affinity Designer is a powerful design tool, and many designers are adopting it as their primary software, even on the iPad. However, ensuring optimal image quality for print, specifically when dealing with raster images and DPI (Dots Per Inch), can present challenges. This article explores how to manage and optimize raster image DPI in Affinity Designer on the iPad, ensuring your designs meet press quality standards.

Understanding DPI and Its Importance

DPI, or Dots Per Inch, refers to the resolution of a raster image when printed. A higher DPI value indicates a greater number of dots per inch, resulting in a sharper and more detailed printed image. For professional printing, a standard resolution of 300 DPI is generally recommended to avoid pixelation and ensure high-quality results.

The Initial Challenge: Checking Image DPI in Affinity Designer for iPad

One user, SharkyAfsar, encountered an issue while transitioning to Affinity Designer on their iPad. They needed to verify the DPI of images placed within their designs, particularly for print projects like flyers. Unfortunately, older versions of Affinity Designer on iPad lacked a direct feature to check the DPI of placed images.

Workarounds and Solutions for Managing DPI

While a direct DPI check wasn't initially available, several workarounds were suggested and explored:

• Checking Document DPI: The document DPI can be checked (and set) in Affinity Designer by going to Document > Resize. This sets the overall DPI for the entire project.
• Using Affinity Photo for DPI Adjustments: One effective solution is to use Affinity Photo in conjunction with Affinity Designer. You can copy an image from Affinity Designer, paste it into Affinity Photo, adjust the DPI settings, and then re-import the image back into Affinity Designer. This video tutorial demonstrates resizing images and DPI adjustments in Affinity Photo.
• Exporting to PDF and Checking in Other Software: Another workaround involves exporting the design as a PDF with specific DPI settings (like 300 DPI). The resulting PDF can then be opened in other software, such as Adobe Illustrator, to verify the DPI of the embedded images.
• Downsampling During PDF Export: Affinity Designer offers downsampling options during PDF export. This feature allows you to specify a target DPI for images within the PDF, ensuring they meet the required print quality. Accessing the PDF export options and setting the raster DPI can be found within Affinity Designer's export settings.

Step-by-Step Guide to Adjusting DPI for Print in Affinity Designer

Here’s a consolidated approach to ensuring your raster images are print-ready:

1. Design in Affinity Designer: Create your design in Affinity Designer on your iPad.

2. Identify Low-Resolution Images: Visually inspect your design for any images that appear pixelated or low quality.

3. Open in Affinity Photo: Copy the low-resolution image and open it in Affinity Photo on your iPad.

4. Adjust DPI in Affinity Photo:

   • In Affinity Photo, navigate to Document > Resize.
   • Enter your desired DPI value (e.g., 300 DPI).
   • Ensure "Resample" is checked to change the number of pixels in the image. Choose an appropriate resampling method like "Lanczos 3 (Separable)" for best results.

5. Save or Copy Back to Affinity Designer: Save the adjusted image or copy it back to Affinity Designer.

6. Replace the Original Image: Replace the original low-resolution image in your Affinity Designer project with the new, higher-resolution version.

7. Export as PDF: When exporting your design as a PDF, check your export settings to specify the output DPI.

8. Verify (Optional): Open the exported PDF in a desktop program like Adobe Acrobat or Illustrator to confirm that all images are at the desired DPI.

Important Considerations

• Image Resolution vs. DPI: Remember that increasing DPI alone won't magically improve a fundamentally low-resolution image. If your image has too few pixels to begin with, increasing the DPI will only spread those pixels out, resulting in a blurry image. You may need higher resolution source images.
• Downsampling High-Resolution Images: Affinity Designer's PDF export settings allow for downsampling images above a certain DPI. This is useful for reducing file size without sacrificing print quality.
• Future Updates: As noted by staff members in the forum discussion, Affinity is continually updating its software. Features like direct DPI checking for placed images may be added in future versions.

Conclusion

While earlier versions of Affinity Designer on iPad had limitations in checking placed image DPI, workarounds involving Affinity Photo and PDF export settings provide effective solutions. By understanding DPI and utilizing these techniques, designers can ensure their raster images meet the necessary print quality standards, producing professional and visually appealing designs. By thoughtfully managing image resolution and DPI throughout your design workflow, you'll be well-equipped to create stunning print materials using Affinity Designer on your iPad.