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October 11th, 2005 #1
Creating a Captured Dab Brush in Corel Painter
Creating a Captured Dab Brush in Corel® Painter™
This week we are going to create a Captured Dab (CD) brush variant. CD variants are made by first creating a graphic element, then capturing it for use as a variant's mark-making tip. This is one of the most personal brushes you can make as the process gives you complete control over the source of the mark made by your brush. There are a few rules you'll need to learn to successfully put CD variant to use. Once you've got these rules under your belt, you'll have a valuable tool for expanding your personal expressivity. Let's go!
Captured Dab Rule #1: Always Make a Copy!
The easiest way to create a CD variant that behaves in a manner that you expect is to start with an existing variant, preferably one that is also a CD variant. Why? Most CD variants commonly utilize a set of settings unique to CDs. By starting with an existing CD variant, you won't have to go through the Brush Controls and adjust all of these settings. Of course, it is important to understand what these settings are, as well as adjusting them for specific brushes. I'll go through these settings later in this tutorial.
Before we even begin, the most important single Captured Dab rule to remember and follow is this: Always make a copy of the source variant that you intend to utilize as your starting point. Why? Besides the usual XML brush description file, the CD variant has an additional JPG file associated with it. This JPG file stores the captured dab. When a new graphic is captured and applied to the source variant, the original JPG file is overwritten. Neither the Undo nor the Restore Default Variant commands can revert this original JPG file; consider it gone. To avoid overwriting an existing variant, always first make a copy to avoid this scenario.
Copying a Source Variant
As I mentioned earlier, the best choice for creating a CD variant is to start with an existing one. For our exercise, we'll use the Square Chalk variant (Brush Selector Bar: Chalk: Square Chalk). Select this variant, then use the Save Variant command (Brush Selector Bar: Flyout menu) to create a copy with a different name. This places the copy in the same brush location that the source variant came from; in this case, the Chalk category.
Examining the Donor Variant
Let's now take a closer look at our copied CD variant. You can look at the original captured dab by going to the Size Palette (Brush Controls) and clicking on the Brush Dab Preview Window to toggle the display to the CD view. We can see that this captured dab is designed to simulate the texture of the tip of a piece of porous chalk. In order to get a better sense of how this CD variant works, we are going to capture our initial dab: an arrow.
Performing Captured Dab Surgery
I've constructed my arrow graphic using the Pen Tool; however, you can just as easily paint one with an existing brush. The final graphic must reside on the Canvas (not on a layer) and should be 100% black. Color will not be recognized; only the Value component matters.
Note: you can take advantage of this by using grayscale values to represent opacity control within the captured dab. For example, a captured graphic created with 50% gray will paint with 50% opacity when used as a captured dab.
To capture a canvas-residing graphic element, you must first select it with the Rectangular Selection Tool (Tool Palette). Note that the rectangle must be a square to avoid introducing geometric distortion into the captured dab. A square selection is created by first placing your cursor at a corner location of your soon-to-be square, clicking down, then holding down the Shift key and dragging to constrain the selection to a square (If you first hold down the Shift key, then make your selection, Painter will interpret this action as an Add To Current Selection option).
With the arrow graphic properly selected, use the Capture Dab command (Brush Selector Bar: Flyout menu) to perform the capture. The Brush Dab Preview Window will update to display the new arrow dab (if it is showing the Max/Min circle display, click on the display to toggle it). Go ahead and try out your new variant (be sure to deselect your arrow graphic; otherwise the new variant will not draw to the canvas). Under some circumstances, Painter will initially use the former dab; in this case, adjusting the brush size a bit will purge the old captured dab and activate the new one.
Because this variant is based on its Square Chalk source, the resulting strokes will interact with the current paper grain. To change this grainy behavior, we'll need to adjust this variant's Subcategory (Brush Controls: General Palette) from Grainy Hard Cover to Soft Cover (Subcategory Pop-up). This will change the variant's behavior to paint a stroke with a solid arrow graphic.
You'll notice that the arrow dab is closely overlapping each painted iteration. Let's adjust the Dab Spacing (Brush Controls: Spacing Palette). The Spacing slider controls the distance between brush dabs in a stroke. The Min Spacing slider specifies the minimum number of pixels between dabs. I've set both sliders to their maximum in my example to prevent any overlapping.
If you take a look at the Angle Palette (Brush Controls: Angle Palette), you'll see that the source variant had the Squeeze percentage set to 74%. Try adjusting this value and you can observe the arrow dab's geometry change. To minimize any geometric distortion with respect to the originally graphic, set the Squeeze slider to 99%. Why not 100%? If the Squeeze slider is at 100%, Painter interprets this to mean that the dab is round (a vestige of the earliest versions of Painter) and will therefore not have any rotational behavior. Setting the Squeeze value to anything less than 100% indicates that rotation will be applied to the dab.
When a Custom Dab is created in Painter, an internal array of dab graphics representing all of the potential sizes and angles is created. These internal representations can get quite large. Depending on the particular system Painter is running on, larger internal arrays can tax system performance. For this reason, it is important to adjust the Size and Angle Steps to acceptable—yet not performance affecting—increments. This is what I call the sweet spot.
There almost always is a trade-off between graphic fidelity and brush performance. The sweet spot represents the best balance of these two factors. If your arrow brush is behaving sluggishly, then you may want to adjust the Angle Step slider (Angle Palette) up a bit. Set too high, there will not be enough angular iterations of the arrow to create a flowing stroke; set too low and the brush performance will degrade.
The same advice applies to the Size controls (Size Palette). I wanted to add pressure-controlled size variation to my example, so I set the Minimum Size slider to 25%. I additionally set the Size Step slider to 10%. I then set the Size Expression Pop-up to Pressure.
My final adjustment was for the Brush Opacity (Brush Controls: General Palette). For this arrow-painting brush, I don't want any opacity changes. I reset the Opacity Expression Pop-up setting from Pressure to None.
Once I have this variant adjusted to my liking, it's time to Save it (Brush Selector Bar: Flyout menu: Save Variant). Note that after saving a variant, your current brush will remain active. My customary practice is to apply the Restore Default Variant command (Brush Selector Bar: Flyout menu) to this variant and then select my new variant from the Brush Variant list. If I want to continue experimenting with new captured dabs, I'll begin the process again by saving this variant with a new name.
What Will Your Captured Dab Be?
With the procedure outlined in this tutorial, you can create the arrow variant, save it, and then start creating your own CD brushes. This is one case where the phrase, "If you can imagine it, you can create it." is true!
Viva la Painter!
Pixels—It's all in how you arrange them!
October 12th, 2005 #2
Nice tutorial, John.
I followed your tutorial, with a few exceptions:
• Before saving a copy of the Chalk's Square Chalk variant, I restored all brush variants in the currently loaded brush library to their default state. (I could have just restored the Chalk's Square Chalk variant to its default state.)
• Instead of creating a new arrow to use as the Captured Dab image, I opened the Selection Portfolio and dragged the Curved Arrow selection onto the Canvas, then filled the selection with black. Then I used Ctrl/Command+D to deselect the arrow shaped selection.
NOTE: If we forget and first hold down the Shift key, then drag a square around the arrow, in addition to Painter IX interpreting the selection as Add to Current Selection, the Capture Dab command will be greyed out.
• With the Angle Step slider set to 25%, Painter IX told me there was not enough memory so I went back to your previous paragraph and adjusted the Angle Step slider to 10 degrees.
A couple of demo images based on John's tutorial, the first showing how Angle Expression: Direction works and the second, just some extra playing around with the brush variant, painting on a Layer, using Color Variability, and adding a colored drop shadow:
Using Captured Dab variants is fun!
In addition to creating custom brush dab shapes for painting a wide variety of more interesting brushstrokes, there's lots more we can do with them by making other brush control adjustments.
For instance, below is an image originally used to demonstrate wet on wet painting using the Watercolor's Eraser Salt variant (that's what the circular "water drops" are). The leaf pattern was painted using one of my Captured Dab variants based on a much larger drawing/inking I did of a rose leaf back in the early '70s. I probably used Color Variability set to "from Gradient" and a Two-Point Gradient. It's been a long time (the file name indicates October 1, 2001) since this was done so I don't recall for sure. Though I didn't think of it at the time, this image could have been painted as a seamless Pattern, then printed to use for wrapping paper, or for whatever other use one might think up.
They can also be used (to borrow David Gell's descriptive word) to "stamp" an image wherever you want, as well as to paint a continuous stroke. The stamp idea could be adapted to use for an embossed or flat signature or logo, for instance. (Ignore the specific examples and just take the general ideas then launch off using your own creative imagination.):
Just to see if it could be done, I painted the two images linked below entirely with the Jin's Firefly Brush only changing color, brush size, and adjusting pressure to control opacity and blend:
Thanks, John, for reminding us of another neat thing we can do with Painter IX and earlier versions! (And for giving me an excuse to play again.)
October 13th, 2005 #3
October 14th, 2005 #4
There are endless possibilities using Captured Dab brush variants, only a few of which can be demonstrated here. Since my previous demo included some fun stuff that's not always practical for people who paint, I'll add an example using one of my custom variants and a few alternate versions of that variant.
Here are a couple of demo images showing how one of my "more for painting" Captured Dab variants works. The first includes only one variation painted over several Paper textures. The second includes more take-offs on the original "Jin's Skip Brush 04" variant, along with a 25% view of the Captured Dab image file:
A few notes on this group of custom brush variants in the second demo image:
When the brushstrokes were painted, the dab angle was rotated 147 degrees while in the black and white Captured Dab 25% view it's at 0 degrees.
You may be able to see that some of the brushstrokes in that demo image are painted with the variant set to Impasto Depth and Color.
For most of the strokes, the variant was set (in the Well section) to Dryout: 17.4. The top row second from left stroke was made with the variant set to Dryout: 6.9 which accounts for the stroke "running out of paint" more quickly than when Dryout was set to 17.4.
The goal when creating the original variant, on which the others are based, was to make a brush variant that skipped over the Paper texture surface allowing the texture to show through and also to have the ending of the brushstroke run out of paint more or less quickly.