There's quite a number of formats you can export to in Photoshop. Here's a quick tip on which format to use and when:
- JPEG - Good for exporting to the web. When it comes to adjusting the quality slider ensure that you're previewing at 100% if possible. Artifacts such as square blocks on anti-aliasing or discoloration is only visible at this zoom level. Also note that this will flatten your image. You'll lose your layers if you were to re-open it.
- PNG - Preserve transparency. They also flatten the image. I used this format for the blog's logo, because if I maintained the transparency I could easily change the background and not worry about having to tweak the header as well.
- TIFF - An interesting format, TIFFs actually preserve transparency as well. Though I've never used them, TIFFs preserve layers. Interesting...
Know any other good formats? Drop a comment below.
Another important thing to consider is the Resolution. I don't mean the width and height but rather the dots per inch.
When working in PS, you'll want to set:
- 72 dpi - for stuff to be viewed on a screen, since that's the resolution a majority of screens use and it will also produce the accurate representation of pixels.
- 300 dpi - for print. Printers use 300 dpi when printing for greater quality. You can print in 72 if the image is small, but it's advised for images that are bigger.
Also note that images of 300 dpi vs 72 dpi will always look much larger. For example, set 1280 x 800 px on an image and toggle these dpi. You'll find that 300 dpi is much much larger... in the view of the screen it is, but in view of the printer it's exactly the size you want: 1280 x 800. Inversely, 72 dpi would be smaller on print.
...at least that's the theory...
Another thing to consider is the color mode:
- RGB - Mostly for viewing on screen. RGB starts black and ends white.
- CMYK - Best for print especially for shirts and press. CMYK images start white and end black.
Black in RGB (0,0,0) is actually about C 75, M 68, Y 67 and K 90. Basically, CMYK colors range further... at least in theory...So, remember this when working. If ever you should print and the colors look weird/different, try changing the color mode to CMYK then printing again (you can preview an image in PS in CMYK by pressing Ctrl+Y)
Before you go freaking out, it's good to remember that most of the time things don't get very specific. Perhaps the only relevant point out of all I've said in this point is the resolution (72 vs 300 dpi).