Photoshop 6 for Windows Bible- P12:If you are reading this foreword, it probably means that you’ve purchased a copy of Adobe Photoshop , and for that I and the rest of the Photoshop team at Adobe thank you. If you own a previous edition of the Photoshop Bible, you probably know what to expect. If not, then get ready for an interesting trip. | Chapter 7 4 Retouching Repeating and Restoring 297 That one action clicking on a state is the gist of what you need to know to travel forward and backward through time in Photoshop. If that s all you ever learn you ll find yourself working with greater speed freedom and security than is possible in virtually any other graphics application. But this represents only the first in a long list of the History palette s capabilities. Here s the rest of what you might want to know Photoshop 6 4- Changing the number of undos By default Photoshop records the last 20 operations in the History palette. When you perform the 21st operation the first state is shoved off the list. In Photoshop 6 you set the number of operations that the History palette tracks in the Preferences dialog box. Choose Edit Preferences General or press Ctrl K to open the dialog box and enter the value you want to use in the History States box. If your computer is equipped with 32MB or less of RAM you might want to lower the value to 5 or 10 to maintain greater efficiency. On the other hand if you become a time-traveling freak like me and have plenty of RAM turn it up baby all the way up 4 Undone states When you revert to a state by clicking on it every subsequent state turns gray to show that it s been undone. You can redo a grayed state simply by clicking on it. But if you perform a new operation all grayed states disappear. You have one opportunity to bring them back by pressing Ctrl Z if you perform another new operation the once-grayed states are gone for good. 4 Working with non-sequential states If you don t like the idea of losing your undone states every state is sacred after all choose the History Options command and select the Allow Non-Linear History check box see Figure 7-27 . Undone states no longer drop off the list when you perform a new operation. They remain available on the off chance that you might want to revisit them. It s like having multiple possible time trails. Figure 7-27 .
