Using the locking buttons at the top of the Layers palette, you can lock a portion of a layer’s pixels, lock the layer’s position, or lock everything down — pixels and position. Figure 15-4 shows the four buttons.
Figure 15-4: By using the Lock buttons at the top of the Layers palette, you can protect your work.
Locking layers is great for protecting your work if you don’t want to edit a part of a layer or move it by accident. Here’s what each button does:
To lock all transparent pixels on a layer so that they can’t be changed, click the leftmost button. With this lock in place, you can edit only colored pixels.
To lock all colored pixels on a layer so that they can’t be edited, click the button second from the left. Only transparent pixels are available for editing.
To lock the layer in position, click the button second from the right.
To lock layer position and all pixels (colored or transparent), click the riost button.
When you use any of the Lock buttons, a tiny padlock appears to the right of the layer’s name.
Of course, you can use any of these buttons in a temporary fashion: If you decide that you want to unlock a portion of a layer, just click the appropriate button again.