If capturing display boxes, you cannot control how many PPI there are as
they are programs in at X number of pixels by Y number of pixels. Resolution
(ppi) is meaningless as it does not change total number of pixels.
The only time you could control that is when capturing an entire screen and
you adjust your overall monitor resolution.
I would leave them as the default resolution--adding more is not generally
going to improve the image and may even soften the edges of the type.
If I need more resolution, say for preflight reasons, I would use nearest
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