Saving screenshots as .jpg or .png? Which is best?

[Spin]

Gurus,

Running Office 2003 Professional. I frequently copy screen shots taken by
another application and paste them into my PowerPoint slides. Someone told
me that instead of saving these images as bitmaps (.bmps) to instead save
them as .jpgs, because the file is a lot smaller. Definitely true! I was
also told that it may be good idea to save as .png. When I was asked why he
said he didn't know but that his wife was a graphic artist and saving screen
shots into .png was the best idea. Anyone know why?

..bmp - ok
..jpg - better
..png - best

 

[Echo S]

PNGs maintain transparency, JPGs don't.
PNGs are not lossy, JPGs are.
In my experience, text usually shows up a bit sharper in PNGs than JPGs
(usually important with screenshots).

There are other, more technical, reasons, too, but I don't think I can
explain them so as to make them actually understandable!

I tend to find PNGs to be close enough to the same size as JPGs -- or at
least not completely out of whack, file-size-wise -- that I just go ahead
and use them instead of JPGs.

Don't get me wrong -- JPGs are not bad, and I do use them. I just prefer
PNGs.