If you are uploading photography or non-vector artwork (e.g. high-quality JPEGs), please make sure they are no less than 150 x 150 pixels at 96dpi or ideally sized at 471 x 471 pixels at 300dpi. If your designs are a mix of photography and design, make sure the embedded photographs used are above the recommended pixel sizes.
If you are uploading photography or non-vector artwork (e.g. high-quality JPEGs), please make sure they are no less than 294 x 294 pixels at 96dpi or ideally sized at 924 x 924 pixels at 300dpi. If your designs are a mix of photography and design, make sure the embedded photographs used are above the recommended pixel sizes.