First off, when you read you’re going to be learning how to prepare an exactly sized web graphic you should know that I’m referring to size as in size of the file, not size as in dimensions. There are many instances where this may be necessary - ranging from uploading photographs to a social networking site to uploading an avatar or signature for an online forum that stipulates a maximum file size. Optimizing web graphics successfully is something that comes with time, but when you’re busy that’s often something you don’t have much of – so here’s my take on how to produce a graphic that matches the maximum size you specify.
First off, you need a graphic. I’m using this technique to create a thumbnail for a video tutorial on 3photoshop.com. When you have your image open, and you’ve completed your edits, go up to the File menu and select the ‘Save for Web’ option to bring up Photoshop’s web output control centre.
Now select the type of format you want to save to, if you don’t have a preference or aren’t sure, select either JPEG or GIF. Then come up to the little ‘Optimize Menu button’ (found next to the preset option, see illustration below for exact location) and give it a click, look through the menu that opens and select the ‘Optimize to File Size’ command when you come to it.
You should now be looking at the ‘Optimize to File Size’ dialogue box (see below). Input the desired file size into the first box, this is measured in kilobytes. The ‘Start With’ option means Photoshop will establish the currently used settings as a base and optimize from there. It will go from pole to pole as it searches for the lightest settings. If you weren’t sure what the best format is and left it set to either JPEG or GIF you should see the next option available – ‘Auto Select GIF/JPEG’. When activated it will decide for itself the optimum format for the type of image you’re working with. Finally the ‘Use’ option is only relevant when working with slices. If you’re not, then ‘Current Slice’ will be the only available option. If you are using slices ‘Each Slice’ will comply with the desired file size entered above on a slice by slice basis. If ‘Total of All Slices’ is selected the preferred file size will account for all slices.
When you’re satisfied click the OK button and you’ll see the ‘Save for Web’ dialogue box once again. If everything has run to plan you should see the recommended settings to save the file and achieve the size of file you requested. Now all you’ve got to do is save the image and you’re done – simple as that!
Hope that helps