We recommend using a high-resolution .jpg or .png. While other file types are supported and can be uploaded into the customizer, we do not recommend using files that include vector graphics since the customizer will convert these images to non-vector images and the quality of the image will be impacted.
For custom designs on small devices (phones, MP3 players, controllers, etc.), we generally recommend using an image that is at least 800px X 800px at 300dpi.
For custom designs on large devices (laptops, gaming consoles, tablets, etc.) we generally recommend using an image that is at least 2500px X 2500px at 300dpi.