A "good" PPI (Pixels Per Inch) depends largely on the intended use of the image. 300 PPI is generally considered a gold standard for high-quality print materials. However, the optimal PPI can vary based on factors like viewing distance and the specific output method.
Understanding PPI
PPI refers to the pixel density of an image, determining its level of detail. Higher PPI means more pixels per inch, resulting in sharper and more detailed images.
PPI for Print
- 300 PPI: This is the recommended standard for professional print work, ensuring sharp text and detailed images in brochures, magazines, and marketing materials. It aligns with the common 300 DPI (Dots Per Inch) requirement of printers.
- 150-240 PPI: Acceptable for less critical print applications or larger format prints where the viewing distance is greater. Examples include posters or banners viewed from afar. Lowering the PPI can also reduce file size.
- Below 150 PPI: Generally unsuitable for print unless the final product is very large and viewed from a considerable distance. Quality will be noticeably reduced at close range.
PPI for Digital/Screen Use
Screen resolution is often measured in DPI, which can relate to PPI, but screens have a native resolution, so PPI matters more when creating an image destined for a screen.
- 72 PPI: Historically, 72 PPI was considered standard for web images because older monitors had a physical resolution around that value. However, modern high-resolution screens render images at various scales.
- Higher PPI (e.g., 144 PPI, 300 PPI): These are beneficial for "retina" or high-density displays, providing sharper images. However, scaling in web browsers can effectively reduce the perceived PPI. Images will still look good even scaled down from a higher PPI.
- Scalable Vector Graphics (SVG): A vector-based format that isn't pixel-dependent. It scales seamlessly to any size without losing quality, making it ideal for logos and icons on the web.
Considerations When Choosing PPI
- Intended Use: Print requires higher PPI than digital display.
- Viewing Distance: Larger prints viewed from further away can use lower PPI.
- File Size: Higher PPI results in larger file sizes, which can impact website loading times or storage space.
- Printing Method: Professional printing often demands 300 PPI, while inkjet printers might produce acceptable results with slightly lower PPI.
Summary
Choosing the right PPI involves balancing image quality, file size, and intended use. For high-quality print, aim for 300 PPI. For web use, consider the target display's resolution and the potential for scaling.
