excerpt from DSU 110, Intro to Photoshop
by Emma Powell
Layers are critical to working with Photoshop. The open
image is a view from above, like looking down at a paper scrapbook layout.
The Layers Palette is looking at those layers from the side, like the
layers of a sandwich. Just as papers and photos on a paper page are layers
and can be moved and overlapped independently from one another, digital
scrapbook pages have the same layers.
The explanatory image in Figure 1 has 5 layers: the white background,
and each of the 4 shapes is one layer.
The view of the example image is from above, as if looking down on a
piece of white paper with four colored paper shapes on it. The view in
the Layers Palette on the right is like looking at the side of the layer
stack, with the white paper (Background) as the lowest layer,
and the shapes on top of it. The active layer is highlighted in the Layers
Palette, as Layer 3 is blue in figure 2.5 above, and a paintbrush icon
in the empty box between the Eye icon
and the Layer Thumbnail.
Using the Move Tool to
rearrange the shape layers, we can see how each layer remains separate
and distinct, independent of the surrounding layers.
Placing each shape near the center of the white paper shows that the
green triangle is the uppermost layer, with the black square beneath it,
followed by the red heart, then the orange circle, as reflected in the
stacking order in the Layers Palette.
To reorder the layer stacking order, simply click and drag any layer
in the Layers Palette to a different location, or go to Layer>Arrange
and choose a new location, or use the keyboard shortcuts of Ctrl + [ or
] to move each layer one position up or down at a time.
Dragging a layer to a different stacking order affects the way it interacts
with the layers around it. In the example, the green triangle on top is
dragged beneath the other shapes, so is no longer completely visible,
but obscured by the higher layers. The new position of the triangle is
visible in the Layers Palette.
The image information isn't lost if overlapped by something else, as
demonstrated with the black square. When separate, the entire shape was
visible. When covered by the green triangle, it was no longer visible,
but the information was not lost because when the triangle was placed
below it, the black square became completely visible again.
If this image was actual paper on a desk, imagine moving the paper shapes
around, overlapping them in various ways. The same concept is evident
in digital layers.
© 2004 Digital Scrapbook Place, LLC