Blockposters may be something you should try out.
As the webpage says…
Upload an image from your computer and choose how many sheets wide
you would like your poster to be once printed
Once you’re happy with your selection, you can download the PDF file
containing your newly created images and print each one massively blown
up, resulting in a huge pixel poster to stick on your wall…
This may be the answer to the problem I’m having enlarging an animal picture I want to use for a mosaic for the Steve Irwin mural.
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