This question, or really “what does it mean to maximize compatibility” comes up a lot in Photoshop classes when people start saving PSD files for the first time. When you save a PSD, Photoshop by default will ask you if you want to maximize compatibility by checking a box. Most people on first sighting of this message box, tend to wonder what that actually means.
Well the reason why this box comes up is because Photoshop is offering you some backward compatibility. Let’s say, for example, you have Photoshop CS4 in work or in the classroom and you have Photoshop CS at home and you want to bring those work files home. Everything you do in the Layers palette needs to be saved with the file. Newer features in CS4 won’t be understood by an older version, so by maximizing compatibility you can make an attempt at having your Photoshop files open on two different versions, so it can be worthwhile.
Part of the problem however, aside from the nagging message box every time you save a new PSD (it only asks you the first time you save), is that as well as saving your layered PSD, Photoshop adds a hidden flattened layer to your file. This obviously makes the file size bigger which is not good new if you’re saving lots of PSDs.
Here’s a simple example to show you how much bigger the file size can be. Below you can see an image consisting of two layers, brown paper on one layer and text on another, no background layer. What you can see here is the actual size. When I save this with Maximize Compatibility checked the file size is 1.68 MB. When I make a duplicate and save it with a new name and turn off Maximize Compatibility the file size is 0.98 MB. That’s quite a bit of unnecessary bloating when compatibility isn’t really required.
So how do you fix the problem. Well if you’re sure you don’t need compatibility between Photoshop versions (and most people won’t if they only have one copy of Photoshop), then you can change your preferences and completely skip the nagging screen.
Choose Edit > Preferences > File Handling and change the “Maximize PSD and PSB File Compatibility” from the default of “Ask” to “Never.” Photoshop will stop asking you every time you save a new file.
If you know for sure that you do need compatibility but don’t want to see the nagging message box, set this preference to “Always” and Photoshop will save with compatibility every time without asking you.
So hopefully you’ll find that little tip useful. It can mean a big saving on file size which is good not just for your hard disk, but also in the amount of time it takes to open the file.
Do you normally maximize compatibility when saving layered files or do you uncheck the box?