Tips and Tutorials

Why a Pencil Variant with the Dab Type Set to Rendered
Produces Artifacts, and Some Things
We Can Do to Get Smooth Brush Strokes

Written by Jinny Brown

NOTE: Painter User comments in this tutorial are paraphrased, not exact quotes.

Painter User Question:


Has anyone noticed the wierd results when using a Pencil's variant with the Dab Type set to Rendered?

NOTE: The following image is not the Painter User's demo. It's one I created for this tutorial but it demonstrates the artifacts he asked about and were seen in his demo image. I don't know which of the Pencils' variants he used but the brush stroke in the demo below was painted with the Pencils' Cover Pencil, Dab Type adjusted to Rendered and brush Size adjusted to 30.0:



My Response:

That happens with the Pattern Pens' Pattern Pen variant too (it uses Dab Type: Rendered, as do several other brush variants). Take a look at these examples done in Painter 6 and read the text below the images. Maybe they'll make you smile while you're figuring out how come this happens and what to do about it. 

Pattern Pen Porpoises, Gabby Grubs, Babbling Balloons, or Who?

Or... Making Lemonade Out of a Lemon

I find the best way to control those "artifacts" is to paint with a light pressure and make the strokes in a sweeping movement with no sudden, sharp turns. If you hesitate, press too hard, or make a sharp turn the brush dab will start to spin and leave more paint.

To see the spin "up close":

Try making the brush size about 150, open a medium-large white Canvas, choose black as the Main Color, then place your cursor in the center of the Canvas and press just a little to encourage the dab to spin. If it doesn't spin, move it around in a tiny, tiny circle until it does, like this:




Just curious, why are you working with a Pencil variant with the Dab Type set to Rendered? None of the Pencils' variants in the default Painter Brushes brush library use that Dab Type so I figure you must have changed it.

If you want a pencil stroke, use the Pencils' variants in their default state, or with minimal adjustments that won't change the entire character of the stroke.

That's my suggestion, anyway. You may have some compelling reason to use Dab Type: Rendered.

I haven't given you a very technical answer, but maybe this will help you understand how Rendered Dab Type variants work.


Painter User Answer to my Question About Why Use Dab Type: Rendered with a Pencils' Variant:


I'm using Dab Type: Rendered because I understand from reading the manual that it produces a superior brush stroke to those made with variants that use Dab Type: Circular which paints circular brush dabs while Dab Type: Rendered paints perfectly smooth strokes.

My Response:

Thanks for sharing your reason for choosing Dab Type: Rendered. That helps us to know what you want so maybe we can help better.

It's true that brush strokes painted with a variant that uses Dab Type:Rendered are generally smoother but not true they're generally superior to strokes painted with variants that use other Dab Types.

It all depends on the look you want and how the brush variant is used.

The Pens' Scratchboard Tool also uses Dab Type: Rendered and strokes painted with this variant can appear entirely smooth and without the artifacts we've been talking about, if it's used at a small enough brush size:



I recorded the left stroke, then increased the brush size and clicked on the Canvas to apply the right stroke. In the left stroke, where I began the stroke, my hand was slightly shaky so you see that wobble in the stroke. Also, as I was applying very light pressure, when you zoom in close you'll see the beginning of the stroke is all anti-aliasing (no black pixels) and in other parts of the stroke where it's very narrow, there's only one black pixel with anti-aliasing on either side so the stroke begins to look a little "flaky" even at 100% zoom (which is what you see above). The problems in the right stroke are very obvious, the start of a "spin" at the beginning and lots of lumpiness along the edges in the rest of the stroke.

Here's another demo but this time with the Pencils' Cover Pencil which is a dab based variant and uses Method: Cover and Subcategory: Grainy Soft Cover. Notice the round overlapping dabs are visible in the right brush stroke where less pressure was applied and the Opacity is lowered, and even along the edges where more pressure was applied and Opacity is higher:



I changed the Subcategory from Grainy Soft Cover to Soft Cover to get the smoothest possible stroke with the brush size at 10.0. At this size (10.0) the overlapping dabs aren't visible but at size 100.0, to make them not appear, we can adjust Spacing to 1%.

In the demo below I adjusted Spacing to 1% for both the left and right brush strokes:



While there's still some lumpiness along the edges of the size 100.0 stroke, it's much less evident than in the first image above, using the Dab Type: Rendered. It's always possible some of that is due to my hand shaking just a bit. You'd have to try it yourself to see how it goes, but this is the combination of settings, of all of the ones demonstrated in this post, that I'd use to get smooth, anti-aliased brush strokes.

If you want your brush stroke to interact with Paper texture you can change the Subcategory to Grainy Hard Cover and adjust the Grain slider:



The result will vary depending on the selected Paper texture. Here I used a Paper from the Painter IX CD, named B_Purple_Pink. I don't remember which Papers library it's in as I've got it in a custom Papers library now. Also, I don't know if it's on the Painter X CD as well, but here's a screen print to give you an idea of how this Paper looks so if you like it and don't have it, you might be able to find something similar or create something similar:




There's lots more, obviously, that we can do to adjust brush variants to make them work the way we want but this should give you a start, and some ideas for adjusting other brush variants.


Cheers!


© Jinny Brown
June 23, 2007

Painter X screen prints are © 2006 Corel Corporation, reprinted by permission.