Hi,  I've been using Photoshop for 6 years and I still don't know what  a PNG file is for and/or what I do with it.  Can someone help?  Thanks!  -Drew

Attached Link: Wiki on PNG

PNG is just a file format, very similar to a psd really only it doesn't keep several layers in one document.  Instead of offering psd  when I create packs I offer them as png because the quality is the same only they don't seem to weigh as much as a psd would for some reason.

O.K., so I can load them and use them just like PSD files?   Practically speaking, the sound the same as JPEGs.

My question would be: does it offer lossless compression or is it lossey like jpg? 

The first sentence in the Wiki article (link provided above): "Portable Network Graphics (PNG) is a bitmapped image format that employs lossless data compression.

There is more useful information and external links in the article.

Yes, you can use them like psd as long as the program you use supports transparency in png's, Photoshop started supporting it with version 6, not sure about psp, I know psp 9 supports it for sure, but I don't know about earlier versions...  And no, it's definitely not like jpg,  you can't preserve transparency  with jpg which is something you can do with a png and you definitely don't loose quality like you do with a jpg.

I knew that but I wanted  someone else to say it; a few years ago  people were  trying to find a  replacement  for jpg  as there were  copyright issues with the compression scheme also the lossy method of compression was unexceptable to some. png was seen as that replacement.

.PNGs are very important to Poser users!

When you open a Poser Library all of the thumbnails are genreated by .PNG files.

Also once you've rendered a person if you want to export the render of the person, without the rest of the image(the Poser scene's background;) for composition here in Photoshop onto say an actual photograph, then .PNG is the only way to export an image with Transparent pixels(the Poser scene background at that point.)

PNGs were essentially developed to save images that would be the same size as JPEGs but wouldn't have the loss and artifacts common to JPEGs.

I have PSP 8 and it supports PNGs. I don't know about any earlier versions. I tend to use TIF files more than anything else these days, so I haven't really messed with PNGs much.

Tiff is a very versitile format - multible images in the same file etc. The biggest problems are limited compression and the fact that there are so many flavors of it; ps uses one corel another psp still another and macromedia another - everybodies got their own idea of how to set it up. (I learned all this when I developed a small utility for Bryce users called Tiffer a while back).

If you're working on your own have and have alot of drive space Tiff can be wonderful to work with - the problem comes in  when you are working with others over limited resources.

.:PNG is great for pretty compatible, high quality transparency. TIFF, as bikermouse stated, is cool if you have the correct software:.

PNG is also used for the creation of websites. It supports transparancy much better than gif, so you can, with the background image feature of Cascading Style Sheets layer several png images.

The downside is, as always, Internet Explorer. There are workarounds, but no real support.