This article is about the maximum size constraints in Blow Up. If you are wondering about how large you can print your photo, please see our answer to this question: "How large can I print this photo?"
The maximum size that Blow Up supports is constrained by a few factors:
1. Photoshop limits all document sizes to 300,000 pixels. So Blow Up restricts the document size to 300,000 pixels too.
2. Photoshop Elements limits all document sizes to 30,000 pixels. If you are running Blow Up as a Photoshop Elements plugin, then you cannot set your document size larger than 30,000 pixels. If you want to resize your image larger than 30,000 pixels, please use Blow Up as a Photoshop or Lightroom plugin.
3. The JPEG format usually limits document sizes to 65,535 pixels. But this restriction may be lower depending on whether you are on Windows or Mac. If you are saving your resized file in the JPEG format, we recommend that you set the image size to less than 30,000 pixels. If you must have images larger than 30,000 pixels, please use the TIFF format instead.