| Adobe Photoshop Basics | |
The layers palette shows you the stacking order of the various layers in your document along with a thumbnail to help you identify each layer at a glance. As mentioned previously, only a single layer can be edited at one time. The active layer will be highlighted in your layers palette. (Continued below...)
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In addition, the active layer will have a paintbrush symbol in the small square just left of the thumbnail. Double-clicking on a layer in the palette gives you access to layer styles, as well as some advanced blending options that we will not be discussing in this course. Unlike previous versions, renaming a layer in Photoshop 6 requires you to Alt/Option double click on the layer name.
You'll also notice a small eye icon 
for each layer. Clicking on this icon lets you toggle the layer visibility on and off. This way you can temporarily hide a layer if it's in your way. Hiding a layer also prevents it from printing. You can easily hide or reveal several layers in a row by quickly swiping across the column of icons as you hold down the mouse button. To hide all layers except one, you can hold down the Alt/Option key as you click the eye for the layer you want to remain visible.
Although editing functions can only be applied to one layer at a time, there are a few functions which can be performed on a series of layers. For instance, moving layers, copying layers between documents, and aligning layers. To perform these functions, you will need to link the layers that you want to work with.
To link layers to the currently active layer, you would click in the second square (left of the thumbnail) in the layers palette. A link icon will appear in the space to indicate that the layers are linked. As with the visibility icon, you can quickly link several layers by swiping across this column with your mouse. To unlink several linked layers with one click, you can Alt/Option click on the paintbrush icon for the active layer. We'll discuss moving, copying, and aligning layers more later.
Now take a look at the bottom row of buttons on the layers palette. These icons allow you to (left to right) work with layer effects, add a layer mask, group layers into sets, create adjustment layers, create a new ordinary layer, and delete layers. For now we're only going to discuss the last two buttons.
If you click the delete layer button, you will be asked to confirm that you really want to delete the active layer. If you want to delete the layer without confirmation, you can drag the layer from the layer palette stack and drop it on the delete button.
When you click the new layer button, a new, empty layer is created above the currently active layer. The new layer will be given a name such as layer 1, layer 2, and so on. If you want to name the layer when you create it, hold down the Alt/Option key when you press the new layer button. To create a new layer below the active layer, hold down the Ctrl/Command key while pressing the new layer button. To create a new layer below the active layer and give it a name, use both modifier keys while pressing the button.
To quickly duplicate a layer, drag the layer from the layer palette stack and drop it onto the new layer button. The duplicate layer will have the same name as the layer being copied, with the word "copy" appended to it. If you want to give it a different name at the same time, you can hold down the Alt/Option key as you drag and drop the layer onto the new layer button.
We'll talk about the other buttons in this palette later on in this lesson.
To change the stacking order of layers, you simply click and drag them into a new position in the layers palette. A thick line will appear to indicate where the layer will be placed when you let up on the mouse button (see screen shot at right).
Now lets look at the options at the top of the palette.
| More About Blend Modes |
| • Blend Modes for Beginners • Layer Blending Modes |
I could take a lot of time explaining how each of these blending modes operate, but to be honest, it involves math and science that I don't fully understand myself; secondly, it's already been done by others much better than I could attempt (see links at right). Besides, working with blend modes is not something you can get a handle on by reading about. This is one of those things that you must experiment with. So, I strongly encourage you to set aside some time and visit the links in the sidebar to the right while you experiment and explore the blend modes. I've selected a variety of links because each one provides different explanations and example images and will give you a better overview of the range of effects you can achieve with blend modes. You can download this example image to your hard drive to use as you experiment. We'll learn some practical uses for many of the blend modes in future lessons.
Next to the blend mode menu is the opacity control for the layer. 100% opaque means that there is no transparency to the layer. In the example shown here, I've adjusted the opacity of the star layer to 50%. Notice how the layers below show through. As you move the slider left, the layer will become more and more transparent until you get to the far left where the layer content disappears entirely.
You can control the opacity level using your mouse with the slider control, or numerically using the number keys on your keyboard. Tapping 1 on the keyboard sets the opacity to 10%, 2=20%, and so on up to 0 for 100%. For even more precision, you can tap two numbers in quick succession to set the opacity to a specific two-digit value, such as 75%.
Take some time to experiment with the stacking order and opacity controls using the example image.
The opacity setting controls the transparency of the layer overall, however, it is possible to have varying levels of transparency in a layer, even if that layer is set to 100% opacity. You do this using the painting tools, eraser, layer masks, and so on. Many of Photoshop's painting tools have their own opacity control that is independent of the layer opacity. I hope that last paragraph didn't confuse you too much, because the next option we'll be talking about is the transparency lock... and it really has the potential to confuse!
Below the blend mode and opacity controls, you have a series of checkboxes for locking various editing functions. From left to right the lock can be applied to:
transparency,
image pixels,
position, and
all of the above.
When any of the locks are activated, you will see a small lock icon appear to the right of the layer in the layers palette. When all locks are activated, the lock icon will turn solid. You'll notice the background layer always has its transparency and position locked. This cannot be changed without promoting the background to a layer.
The transparency lock allows you to edit on a layer without changing the transparency level of the pixels in that layer. The best way to explain this is with an example.
In the image we've been working with, set the opacity of one of the layers to 50%.
Now pick a color (I used green) and fill the layer with that color.
Result = the entire layer is filled with the color giving the layer a 50% green tint in my case.
Now undo that change and check the transparency lock. Fill the layer with your color again.
This time, only the layers where there were pixels are filled, and those pixels retain the same transparency values that they had before you filled the layer. 50%, in this case.
This transparency lock effects any type of editing you do on the layer, including painting, filling, and filters. For another experiment, try the gaussian blur filter with transparency unlocked, then undo and apply it again with the transparency locked.
The transparency lock isn't that difficult to understand, really, but it has the potential to really confuse you if you select it at some point and then forget that it's turned on! Whenever you encounter a tool or function that just doesn't seem to be behaving as it should, check to see if this or any of the other locks are selected before you panic.
The image pixels lock disables all painting tools for that layer. You can still move and transform the layer contents, adjust opacity settings, and change blend modes, but you cannot paint directly on it.
The position lock is self explanatory. You can't move or transform a layer that has its position locked, but you can still paint on it, apply layer effects, and change blend modes.
And if you hadn't guessed already, the last lock is the same as selecting all three locks.
