Merging and flattening layers

- [Narrator] As your documents begin to contain…more and more layers,…sometimes those file sizes will grow to be quite large.…So people are always looking for a way…to reduce the file size,…but unfortunately the different ways that Photoshop has…to merge layers or to flatten images,…also removes some of their flexibility.…But let's take a look at them…so that you can decide for yourself.…Right now at the document size in the lower left hand corner…you can see that if this document was flattened…it would be about 12 Megs.…

But as a layer document it's 52.4 Megs.…So let's see if we can get that file size down.…Now one of the ways we could do this is by…cutting or cropping any extra information…that's actually outside of the visible canvas area.…So when we first brought this orange file…into this document,…it was actually a little bit bigger.…So there's actually some orange that is kind of…hanging out here, outside of the canvas area.…

So if I wanted to crop that I could do a quick Select All…and then in Image, and then Crop, and we can see that now…