I had this debate with a colleague and we didn't see anything solid or something from a search that would answer this with certainty so I thought I would open it here. You are designing a website or app in Photoshop what is the preferred method for printing a proof for a client appointment in regards to getting the best color accuracy?
The premise of the question is flawed for a few reasons.
A print proof is meant to mimic the final product. The idea is that you view the proof with the expectation that the final product will look exactly like that.
That concept doesn't exist on the web. For a number of reasons:
There is no defined canvas size. Unlike a piece a paper, a web browser can be nearly any size. (Nor may there even be a canvas in the context of something like a screen reader)
There is no defined screen size. Screens come in all sizes and shapes and pixel densities.
There is no defined software. Everyone will be using a different browser on a different operating system with different settings.
The web is interactive. Even if you COULD define all the above, a user can quickly change that.
I like to explain the difference between print design and web design as such:
print design: You are dictating a very specific visual presentation.
web design: You are suggesting one possible visual presentation for specific data.
The bottom line? You don't use a printed PhotoShop file as any sort of 'proof' for web design.
Ideally, you show the client working HTML, CSS and JS. That lets you see the 'big picture' including variances, interactions, etc.
You can certainly show a mock-up as a way to explain how the site is going to roughly look, but that's all it is. It's just showing how it's roughly going to look.