Upresing Image

I think we need to get this out of the way: you do not need 300 ppi for large format prints. That's a very common misunderstanding. As size goes up, ppi requirement goes down, because it will be seen from a greater distance. Large wall-sized banners can be as low as 15 ppi and still look razor sharp.

A good quality image will work at any size, whether magazine spread or roadside billboard.

Even so, 300 is not a magical number. 300 ppi is for book and magazine print to be seen from less than arm's length. This is usually printed with a line screen frequency of 150 lines per inch. With an original image at 300 ppi, that means individual pixels can not possibly be distinguished in the final print.

In other words, 300 ppi is a theoretical upper limit, beyond which no improvement is possible. 300 and 400 is all the same, you can't see any difference. But you can go quite a bit lower before you see any noticeable drop in sharpness.

Hi Sylvia,

I also have had to upscale images because of not having an original to go back to--I agree sometimes it can't be helped. I have had really good results through the years at uprezing at 150% until I get to the size I want and have had some very good results.

Let us know how it turns out!

Michelle

"in this case, it cannot be helped"

Why, exactly, can it not be helped?

19 x 12 inches at 300ppi is 5700 x 3600 pixels. That's not a particularly small image! In fact, it's big enough to work as-is for almost any practical purpose, if the image is otherwise of good photographic quality (in focus, no camera shake etc).

I'm with Nancy on this. Upsampling is almost always a bad idea, no matter what fancy algorithm you use. There is absolutely nothing to be gained, but a whole lot to lose in terms of artifacts which you always get with upsampling.

The only justification for upsampling, ever, is if you can actually see individual pixels. 60 inches wide just means you'll be seeing it from a greater distance, so the effective optical resolution stays the same. You'll want to step back. The eye demands it, so that you can take in the whole. Standing up close is physically uncomfortable.

You will always get the cleanest result by leaving the file as it is. Instead, spend your energy on optimal sharpening.

The best place to start is using Image Size with Preserve Details 2.0 selected as the Resample method. It should preserve details much better for enlargement than any other choice in the Resample menu.

But the higher the percentage of enlargement, the less the details might hold together. If the resulting file doesn’t meet your standards, you may need to use specialized upsampling software such as Topaz Gigapixel AI, which is well-regarded for this kind of thing, but requires a powerful GPU and is another $100.

Also, ask the metal printing service what ppi resolution they recommend for a work of that size. 300 ppi is probably not recommended because it would create a very large file size at 60 inches, and if the work is designed to be viewed at a distance, a lower ppi resolution will be perfectly adequate. I just don’t know what the guidelines are for ppi on metal at specific art sizes and viewing distances.

As a rule, up-sizing images is a very bad idea.  Adding pixels where none exist introduces unwanted artifacts and pixelation.  That said, I would discuss this with the print professional.  They will know what the best approach is for the paper, size, ink and process they are using. But don't expect miracles.  60 inches is a far cry from the original.

can you share this image?