I didn’t realise that PNG file sizes could vary so much. I was taking a screenshot using Windows, and initially, saving it in Paint, and then using Microsoft Office Image Manager to convert it to a PNG. Then I discovered the machine I was on had Fireworks, so I pasted directly into that, and saved as a PNG.
The Fireworks PNG was around 3-5 times as large as the other one. I would have pegged it as being the other way around.
I actually came across a program I had downloaded the other day that is a one-trick pony - it compresses PNG images. This made a similar difference in sizes.
