There are two types of graphical file formats — vector and raster. Procreate is a raster art application. With raster graphics, actions you take, such as transform, can impact image quality.

Unlike vector images, which use scalable mathematical lines or paths, raster images are comprised of a fixed number of pixels per inch (PPI). These are arranged in a grid and are resolution dependent. Manipulating this grid of pixels into new angles or enlarging their size without increasing resolution can affect the array of pixels by adding or removing them.

This is called interpolation, and you can read more about it in the handbook .

The impact of scaling raster images

If an image is scaled to a larger size, a new image with more pixels must be generated and rendered. This can result in pixelation or blurring of the image.

The impact of transforming raster images

If you rotate or transform a raster-based image the original grid will adjust some pixels to adapt to the new angle. These pixels won’t return if the image is transformed back to its original angle. It will have less pixel information to fill that space, which can result in pixelation or a loss of quality.

Improve transform results with interpolation

You can improve transformation results by selecting the best interpolation setting for your workflow. By default, the interpolation settings for Transform in Procreate are set to Bilinear. Try selecting Bicubic for smoother, improved Transform results, or Nearest Neighbour for faster Transform results.

Find out more about the different types of interpolation and how they affect Transform in the handbook .

Why use raster?

The advantage of raster images, commonly used in photography and on the web, is their adaptability and compatibility. They are not tied to proprietary software or file formats.

The file formats .jpg, .tiff, and .png are all general raster images. With good planning of resolution choice for your image, they are suitable for both digital and printing purposes.