Guest article by Ben Chamberlain of Supermassive Black Hole A*.
This article discusses drawing with Photoshop’s Lasso Tool, with specific examples from the Windows version of Photoshop CS2.
In Photoshop, the Lasso Tool, located near the top of the toolbar, is typically used for selecting irregular sections of an image: click the tool’s icon on the toolbar, then draw a shape on your image, and that shape becomes a “crawling ants” selection area, ready to be edited with filters or other tools.
You can, however, use it as a drawing tool. Why would you want to do that? Possibly for one of these reasons:
Drawings made with the Lasso Tool look distinctly different than drawings made with the usual Pencil, Brush, or Pen tools; the Lasso Tool, then, might be useful if you want to achieve a different look.
The Lasso Tool is very flexible in terms of the shapes it can make; even the finest use of pressure sensitive drawing tablets in conjunction with the Brush cannot achieve the range of wide and narrow, curved and pointy filled shapes that the Lasso Tool can capture in a single stroke. This makes it useful as a rapid layout tool for sketching the base of what will become a complex drawing, for instance.
Shapes made with the Lasso Tool can have the sharp, high-contrast, curving, and perfectly filled qualities of shapes drawn with vector tools, but are not actually vectors, so they are editable with Photoshop’s full array of filters at every stage of the drawing process, and never require editing of vector points.
Because every shape created with the Lasso Tool is also a selection, it is useful for creating solid shapes that will be moved over other layers in animation.
Basic Lasso Drawing: Fill
Drawing with Photoshop’s Lasso Tool is a two-step process: first you draw the shape as a lasso selection, then you alter that area to make a mark in the shape you just drew as a selection. Here’s a simple example:
With the Lasso Tool selected in the toolbar, check the options bar, which is usually at the top of the Photoshop window:
You’ll see the Lasso Tool’s “Feather” and “Anti-alias” options there. Unless you are trying to draw something blurry, like a soft shadow, you will want to have “Feather” set to “0.” If you are drawing at high print resolutions such as 300 or 600 dpi, then you may want to uncheck “Anti-alias” in order to make other things like Magic Wand selections easier later on; otherwise, I suggest having “Anti-alias” checked, as this will prevent the shapes you draw from looking jagged.
With the Lasso Tool’s options set the way you like, go ahead and doodle a shape on the canvas. When you release the stylus tip or mouse button, a “crawling ants” selection is left in the shape you just drew.
Now use the “Edit > Fill” menu item (or the keyboard shortcut, “Shift+F5”) to fill the selected area with the foreground color. Clear the selection (keyboard shortcut “CTRL+D,” or just click somewhere else on the canvas), or hide the “crawling ants” (keyboard “CTRL+H”) to see the shape clearly.
Brilliant! If you like, you can draw more lasso selection areas and Fill them to continue fleshing the shape out. You can also switch to a different color, such as white, and lasso and Fill with that to add interior details.
Voilà! Your first lasso drawing. Fill, however, requires going through the Fill dialog window and clearing the selection afterwards, which slows down the drawing process. Fortunately, there’s another approach that is much more direct, although it requires a little set-up first.
Intermediate Lasso Drawing: Cut
When you have a selection on the Background layer of an image, the Cut command (“Edit > Cut,” or keyboard “CTRL+X”) replaces everything inside the selection with the current Background color; in effect, it fills in Lasso Tool selections, without having to go through a cumbersome dialog window.
It is important to note that this only works on the Background layer; using Cut on a layer above the Background simply makes a hole in the layer. The Background layer is shown at the bottom of the Layers window as a layer named “Background” in italics.
A new canvas will always have a Background layer by default, but the Background can be destroyed by various means, such as deleting the layer outright, or by converting it into a regular floating layer by moving it with the Move Tool or double-clicking it and clicking “OK” on the “New Layer” dialog that appears.
If the Background layer has been deleted or converted to a regular floating layer, the only way to get a Background layer for that canvas is to use “Layer > Flatten Image” to squish all layers down into a new Background layer. This is usually not desirable, so if you intend to use lasso drawing in an image, make sure you leave the Background layer intact!
Now, let’s see how using the Lasso Tool and Cut on the Background layer can be used to draw a shape. First, we select the Lasso Tool and draw a selection area in the shape we want:
Before using Cut, make sure you know what your Background color is; it needs to be different than the color currently covering the Background layer in order for a drawing to be made when we cut. The Background color is always displayed as a square near the bottom of the toolbar, overlapped by another square, which is the Foreground color. By default, Photoshop will have black as the Foreground color, and white as the Background color.
The smaller icons around the Foreground/Background icons are important for lasso drawing as well: the small, overlapped black and white square icon at the lower left returns the Foreground/Background colors to the default black/white configuration, and the double-headed bent arrow icon at the upper right swaps the Foreground and Background colors. It will be useful to memorize their keyboard shortcuts: “D” for default colors, and “X” for color swap.
By default, when you make a new canvas in Photoshop, its Background layer is filled with white, and white is also set as the Background color on the toolbar. We need black as the Background color in order to leave a mark on the white Background, so we press “X” to swap the colors, and we can see that this has taken place by the reversed colors now shown in the color squares on the toolbar.
With black as the Background color, we’re ready to Cut out our selected shape. Use “Edit > Cut” or its keyboard shortcut, “CTRL+X,” to Cut the selection area. And there’s our shape, filled with the Background color, and with the selection already cleared for us.
That was faster than fill, but having to press “X” whenever we want to swap colors and “CTRL+X” whenever we want to Cut could get laborious. Fortunately, if you have a drawing tablet, it probably has a stylus with at least two buttons on it that you can set to act as keyboard functions in the tablet’s control panel application.
For instance, my Wacom Intuos 3 tablet’s stylus has two thumb buttons, so I used Wacom’s included control panel application to make one of them function as the key “X,” for color swap, and the other as the key combination “CTRL+X,” for Cut.
With that done, lasso drawing in Photoshop is simply a matter of drawing a selection shape with the Lasso Tool, thumbing the button mapped to “X” to swap Foreground/Background colors if necessary, and thumbing the button mapped to “CTRL-X” to fill the selection with the Background color–while on the Background layer, of course.
Once you’ve got a fast means of swapping and Cutting like that, you can build up complex lasso drawings very quickly: each alteration cuts away to whatever the current Background color is.
You don’t have to worry too much if a shape is too big or too small, because a) if it’s too big, you can just swap colors, lasso-select the part that’s too big, and Cut it away, or b) if it’s too small, you can just make another Cut with the same color to enlarge it.
Here I add detail with various little Cuts, alternating between black and white:
Draw, swap, and cut as many times as you like, and you’ll find that you can build up these little cuts into complex drawings.
If you’ve followed all that, then congrats! You can now generate lasso drawings with the best of them. And if you want to get really advanced, you may find it useful to map the keyboard “Shift” and “Alt” keys to buttons on your tablet.
Once you’ve drawn a selection with the Lasso Tool, you can add to it by holding Shift while drawing another selection shape, or subtract from it by holding Alt while drawing another selection shape through the current selection.
Advanced Lasso Drawing: Layer Masks
The Background layer is not quite the only layer on which Cut does a nice fill with the Background color instead of cutting a hole: “layer masks” also Cut to the Background color, which makes them a good way to carve shapes on floating layers.
While you can’t actually lasso draw in two colors this way as you can on the Background layer, you can make single-color shapes that can then be used as masks themselves, and filled in with detail from another layer, or colored with other tools.
This type of lasso-drawn layer is useful, for instance, if you want to be able to go crazy with lasso Cuts on a figure without losing its outline, or if you want to have a nice contiguous shape that can be moved over other layers in animation.
You can also use this to make shapes of a color other than black or white, and use opacity or blending options on the layer to apply that color and shape to lower layers.
This sounds complicated but it isn’t really, so let’s just see how it works. Let’s say we want to have a black-outlined character on a white Background, and we want to be able to draw a lot of interior detail on the character without risking cutting chunks out of its overall shape, or we want to have it as an independent layer that we can move around over the Background. Because the outline will be black, we set things up as follows:
- Fill the Background layer with black (one fairly fast way to do this entirely with shortcuts is: “D” to reset to default colors, “X” to swap black to the Background color, “CTRL+A” to select the whole canvas, and “CTRL+X” to cut it away to the black Background color)
- Click the “Create a new layer” button in the Layers window to make a new layer above the Background
- Make sure you have the new layer selected, and that white is your Foreground color, then use “Edit > Fill” to fill the new layer with white
- With the new layer still selected, click the “Add layer mask” button to give it a layer mask
When you’re done with that, you should have something resembling this:
Make sure you have the thumbnail version of the layer mask selected in the Layers window, set black as your Background color (notice that the Foreground/Background colors with the layer mask selected are independent of the regular Foreground/Background colors), then use the Lasso Tool with Cut to carve out the silhouette of your figure:
That’s our mask done! Now we can go Cut away interior details on the Background layer without mussing up our nice silhouette.
Once the detail work is done, you may want to liberate your figure from the Background layer so you can move it around. Because we have its shape in the layer mask, this is easy: while holding the “CTRL” key, click on the layer mask’s thumbnail in the Layers window. This creates a “marching ants” selection of everything around your figure–all the white areas in the layer mask:
In the Layers window, drag the Background layer’s icon onto the “Create a new layer” button: this creates a duplicate of the Background layer as a regular floating layer just above the Background.
If you had the “Anti-alias” option box for the Lasso Tool checked when you drew your silhouette in the layer mask, you’ll need to de-fringe your selection so that you don’t end up with little white bits along the edges of your shape, which will be visible and ugly if you move it on top of a layer of a different color.
To remove this fringe, pick “Select > Modify > Expand” from the menu, and use “1” as the “Expand by” value in the window that appears. There are probably less destructive ways to de-fringe, but this one’s fast, and as long as you’re working at less than 100% zoom–unlike me in this lazy example!–you really aren’t risking obliterating any meaningful detail.
With your around-the-figure selection ready, and Expanded to eliminate Anti-alias fringing if necessary, make sure you have your new duplicate of the Background layer selected in the Layers window, and Cut: there’s your detailed lasso-drawn figure, floating free in its own layer. You can now delete the layer above it–the one with the layer mask–and clear the Background layer for your next drawing.
For this quick and dirty example, I was working–with the Anti-alias option on–at 100% zoom; I’m used to working at 50% at most, and you’ll notice I didn’t leave quite enough edge for working at 100%, so the single-pixel Expand took away a little more black edge than I had left room for:
However, if you are working at lower zoom percentages–higher resolutions, in other words–then trimming off a single pixel around the edges won’t really be noticeable.
It is worth noting that not all Lasso Tools are created equal; many image editing programs have a lasso function, and some of them work differently than Photoshop CS2’s Lasso Tool.
I do most of my lasso work in the creaky old Photoshop 4: the Lasso Tool in that version of Photoshop responds instantly, while I find that the one in CS2, by comparison, is slightly slower to update while drawing. On the other hand, CS2’s lasso is a little better at creating a smooth outline, whereas the lasso in 4 tends to leave somewhat rougher edges.
Another lasso of note is the default Shapes module in a compact program called Alchemy (available for Windows, Mac, and Linux). In Alchemy, whatever you draw as an outline, lasso-style, can fill instantly, so lasso drawing there is a one-step process, rather than Photoshop’s select-then-fill two-step process.
Furthermore, it can lasso draw at variable levels of transparency. Alchemy is designed as a fast conceptualizing tool, and doesn’t do fancy things like Layers or even Undo, but it has a nifty export function that pops sketches made in Alchemy directly into Photoshop, or whatever your editor of choice is. As of this writing, Alchemy is at a “Beta” stage, and available as a free download.