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I've written this section to introduce the beginner to layers, and refresh the memory of those that may have forgotten a fine point or two. If you're starting off, I envy you because you're starting a voyage of discovery. I must caution you that it's going to require skull sweat on your end to complete the cruise. Still, the rewards at the end are well worth the effort. Just take your time and study at your own rate. Going slowly, but understanding each point may take time, but you'll understand the subject. Are Layers really necessary? No. People have painted on a single layer for centuries, going all the way back to the first caveman that applied colored mud to the cave wall and realized it was pretty and/or instructive. However, layers allow us to do things that could not be imagined a century ago. Even the effects that layers allows us to do as commonplace would amaze graphics artists of a few years ago. When you start using layers, you'll soon wonder how you ever did without them. |
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Here's a image made up of four layers. A purple flower on top of green leaves, on top of a sky background, all of which is overlaying the Default (or Transparency Checker-Board) layer. The uppermost paint hides painting on lower layers. If there is transparency in all layers, you see the Checker-Board. As you can see, layers are much like painting on layers of glass. Each layer can be moved individually, from side to side, up and down and even have it's position in the stack of layers changed. Click here to download the zipped tutorial image file (300k).The image above is a demonstration of the layers effect in the PSP 6 program. You always view the stack as if you're directly above the stack, looking down and the layers are stacked together. (there will be NO distance distortion.) Unzip and load the image PurFlower.PSP into PSP. Open the Layers Palette. If the Layers Palette isn't visible, toggle between viewing and hiding the Layer palette, using any of the following: · Press L on the keyboard, · Click the Layer palette button on the toolbar, · Right-click the empty space of a palette or bar and choose it from the menu, or · Choosing View > ToolBars and select its checkbox in the Toolbars dialog box. 
Practice clicking on the "Layer Visibility Toggle" icons for each layer. (The icon looks like a pair of glasses.) Try turning all layers off to observe the Transparency Checker-board. Then turn on one layer at a time. When you click this icon, it doesn't change the image, just how it's currently showing. Another item of interest at this point is that the Palettes have a 'Rollup' feature. They'll collapse into the title bar, unless the Rollup feature is dis-abled. I place the title bar up in my tool bar, so it's out of the way during normal painting operations, then when I click it, it drops into view. In the upper right corner is an arrow pointing down to a short horizontal bar. This is the indicator that 'Rollup' is enabled. Left clicking on the icon once will remove the bar and keep the palette on screen without rolling up. Clicking the icon again will restore the Rollup. Once you click anywhere inside the palette with rollup enabled, the palette will stay on screen until a position off the palette is clicked. I usually use the blank area under the Color value display on the right side of the screen to accomplish that. 
The basic feature of each of the layers (starting at the lowest) is: The Transparency Checker-Board This is the image you'll see when there is no paint above it. You're looking all the way to the bottom of the stack. There is no way to put an image on this layer, nor can you make it transparent or hidden and it's position is always fixed at the very bottom of the stack. The only control you have over it is from the File-Preferences-General Program Preferences- Transparency. 
You can change the size of the Checker-board, Small, Medium, or Large, and the color. I usually find the defaults of Grey and Medium size to be satisfactory, but it's your choice.
The Background Layer
This is the default, created whenever you open a New image (unless a transparent color is selected.) or a single layer image, such as a *.JPG is opened. 
Opening a New Image with any color in the background creates a 'Background' layer, while... 
Opening a New Image with a Transparent background creates a 'Layer' layer with the number 1 appended to it, as the basic layer. (note the transparency checker-board showing through the layer) Opening an Saved image will restore the layers that were saved in the original image, defaulting to 'Background' if layers are not supported in the image. So- what's so important about the 'Background' Layer? The 'Background' layer is normally completely covered with paint, with no areas of transparency. If you use the Eraser tool on this layer, instead of erasing to transparent, you'll erase to the Secondary Color in the color swatches. This also holds true for filters. Many of the common filters will erase some pixels, with the assumption that the erase will go to transparent, in place of a color. Therefore, running a filter with the Background layer is a chancy situation. What if I want to use filters on the Background layer, or erase parts of it to transparent? 
Open the layer palette, Right click on the Background name, then select 'Promote to Layer'. The Background layer will be renamed to 'Layer#' and all of the features of a standard layer become available. (# is a number depending on the current number of layers.)
The standard Layers These layers are grouped into Three main types, with sub types.
Raster layers are used with normal Pixel Painting techniques. The paintbrush smears paint as per the brush setup, and all of the raster tools create an image on the layer. The size of the layer will be the same as the originally opened image and the raster layer will open fully transparent. There are two ways to create this layer, by opening a New image with transparent background selected, as was shown in the Background section, or by Layers, New Raster Layer, or by opening the Layer Palette- 
and clicking on the New Layer Icon. Likewise, you can delete layers by selecting the layer you want to delete, then clicking the Trash can Icon, or click Layers, Delete from the menu bar.
A Vector layer is different from a Raster layer in that the Vector layer will have Sub-layers. A Vector layer has a '+' before it, clicking on the '+' will reveal all sub-layers and change the symbol to a '-'. Normally, each individual shape will be on it's own level. 
I drew a funky oval with the vector tool, which created a vector layer, and the sub-layer 'Drawing'.
I then drew a Triangle, then a rectangle. I renamed the vector layer to Vector7 (from outer space?)
by Right clicking on the layer name, selecting 'Properties' from the list, which automatically brings
up the Properties list, with the name already selected. All you need to do to change the layer name is
type it in and hit the OK box.
The image above shows what happens when you pause the cursor over a layer for a few seconds. A thumbnail of the image for that layer pops up for a short time. Left clicking on the layer selects the shape AND by holding down the Ctrl key, and selecting other shapes, you can select a group of shapes that will be treated as one. This is a nice way to move multiple shapes, change their properties as a group, re-size, etc. This effect is only for vectors, since only vectors have sub-layers. The vector shapes stack up, just as layers stack, with the last created on top. You can change the order of the stack by moving the sub-layers up or down, as described in the next section 'Arranging Layers'.
 Adjustment layers are created by using the
Layers command on the Menu bar, holding on the New Adjustment Layer until the options come up.
Clicking on one of the options creates the Adjustment Layer. Sorry, but descriptions of the various options available are outside this tutorial. The effects of an adjustment layer are from the position of the adjustment layer, to the bottom of the stack. When the Adjustment layer is created, the control box for that option will open, allowing you to make the adjustment. Clicking the OK box will close the box. To re-open the adjustments later, to fine tune after other operations have been made, you can double-click on the layer name in the Layer Palette- (this will leave the layer palette open) or Right click the adjustment layer, pick Properties, and the adjustment box will open. (clicking the adjustment tab may be required.) This method collapses the Layer Palette. Caution! When you open an adjustment layer, with an active selection in the image, the selection will be embedded into the adjustment layer as the only active area for the adjustment. Subsequent adjustments in the layer will operate as if the selection is still present, even if the original selection has been deleted.
Arranging Layers in the stack. 
From the Menu bar, click layers, Select a layer to be moved, or just click a layer from the palette. The Layers command allows you to click "Bring to Top", "Move Up" (1 position), "Move Down" (1 position), "Send to Bottom". 
Another way of doing the move is to open the Palette, click on the layer name and drag the layer into position. Note that the layer name does not move with the drag, but a dark line is placed between the layers where the layer is to go. In the image above, I've left clicked the layer Bird 3, and have dragged to between Cloud C and Bird 1. If I release the button, Birds 1 and 2 will go above layer Bird 3. Note that the cursor becomes a 'Banned' symbol when moved off the stack. This may make it difficult to position a layer at the top or bottom of the stack. Incidently, You can not only drag a layer up and down in the stack, you can drag it to another image on the workspace and Duplicate the Layer instantly. It sure beats Edit>Copy followed by an Edit>Paste as new Layer! Dragging a layer from the Layer Palette into the desktop area creates a new image from that layer.
There are three tabs that make up the right side of the Layer palette: Appearance, Mask, and Group. The Appearance tab controls the opacity, blend mode, and transparency lock state of each layer. The Mask tab controls the enable mask and link mask to layer options. The Group tab controls the layer groups. Controlling Layer Appearance. 
Note: Opacity is the opposite of Transparency. An image that has 100% Opacity, has 0% Transparency, while an image that has 0% Opacity has 100% Transparency. The Layer Appearance tab (first of the icons on the right. I've never quite decided what it represents.) displays the 'Opacity' sliders. (which are called "Thumbs" with an upper and lower display thumb.) Clicking and dragging a thumb controls the amount of Opacity/Transparency of the layer. Note that the transparency of Any layer can be controlled, except the Background. This allows many special effects, such as blending a 'Duplicated' Layer, with the Original layer with a filter effect applied to one of the layers. This 'merging' of the pre-filtered and post-filtered images gives controlled application of a filter effect. Remember that the layer transparency controls the transparency of the entire layer! There are other tools and methods which will control smaller sections, such as the eraser- Select & cut- Masks. Next to the transparency sliders are the 'Blend' mode selections. Clicking the arrow next to the window brings up a list of the methods the current layer will be used. Normal makes the layer a 'Stand-alone' display. Other modes cause the current layer to control the appearance of all layers under the current one. (sorry, but a full explanation of these effects is outside the scope of this explanation.) The Lock Transparency restricts the editing of raster layers to the pixels that already contain data. You can select and edit the data on a protected layer, but you can not cover, deselect, or paste to any transparent area. This option does not apply to vector and adjustment layers, so their buttons are unavailable on the Layer palette. By default, the Lock Transparency button of a layer on the Layer palette displays a red “X” because this option is not active. Use either the Layer Properties dialog box or the Layer palette to activate this option on a layer. If you've selected an area of an image, then used Selection- Promote to Layer, and you only want to edit the Non-transparent areas, make the lock active.
Controlling Mask Options. 
Notice there are Two Mask Icons on the top bar of the Layers Palette. The one on the left with the red sparkle is used to create a New Mask for the selected layer. The one on the right selects the Mask options. This may be a good place to define a Mask, as used in PSP. A Mask is an edit able image that controls the transparency of the layer it's associated with. With the mask, you can paint an image which controls the transparency of every pixel in the layer to one of 256 levels of transparency. If this doesn't make sense, just keep it in mind as it's a difficult concept for some. The Mask Icons in the layers named "Promoted Selection" and "Layer2" to the left of the View icon means that the layers contain active masks. On the right side of the palette, layers which do not have a mask will have the options 'Grayed' out. If a mask is present, you can view the image with the mask 'On' or click the mask icon on the Right side to turn it off. Turning it on and off does not effect the actual mask. The Chain Link icon indicates that the layer and it's mask are locked. To move the mask and layer independently, click the link.
Layer Groups Let's say that we'd used layers to create a new image, showing the sky, three clouds, and three birds. Click here to download the zipped tutorial image file (190k).During the paint process, we named our layers: Sky, Cloud1, Cloud2 Cloud3, and Birds A, B and C. (either by creation of the layer, or by right clicking on it's name to bring up the properties box, then typing in a new name.) Now, we spent a lot of time getting Cloud B and C, plus all of the birds into the correct position in respect to each other. If we move a bird, or a cloud in the BC combination, we want to keep all in the same relative position. NOTE: When you use the Move tool (looks like four arrows pointing NESW) and you have a layer selected, but click on a transparent area of that layer, the tool goes to progressively lower layers, until it finds a non-transparent color! Important Point! Always select the layer, and pause over the layer until you see a thumbnail image of the layer, so you can identify painted areas to click and drag with the move tool. 
By clicking the last tab of the palette options, we can place layers into 'Groups'. Initially, all layers are in the 'None' group. By clicking on the box, the groups cycle from 1 to 7 and back to None. By placing the bird layers into the same group, when one is moved to a new location, they all move to the same relative position. The same holds for clouds B and C, although cloud A is independent. Unzip the file BirdCloud.zip and load it into PSP. Start by putting all layers into the None Group. Use the Move tool to move the individual layers around. If you accidently move the background, do an edit-undo to put it back in position. Put any two birds or clouds in a group, move the layer and observe that the grouped layers move as one. Put the three birds in a formation, then group them, and move around the screen. A few minutes of practice should show how easy this feature works. |
PSP 7 background icon. New for PSP 7. There is discussion
about deleting the Background layer totally. Perhaps in PSP 8?
Raster
Vector
PSP 7 has a new 'Gouping' icon to indicate a group
of vectors forming a shape. This layer will be created by drawing one of the saved shapes. It's
sub-layer icons will be the same as vector drawings.
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I hope you've enjoyed this trip into the PSP 6 world of layers, and you now have a better idea of how they work. Let you imagination soar and paint away, using layers to hold individual items that are stacked, photos with adjustment layers, arranged groups that move as one, but retain individual details. Paint well- Ron Vick |