How to Work with the Adobe Illustrator Blob Brush Tool

Learn how to work with the Adobe Illustrator blob brush tool from expert Will "Focus" Dubois in this Howcast video.


This is how to use a blob brush in Adobe Illustrator. In Illustrator you want to go over to your tool channel and you want to scroll down your tools. You're gonna come across the brush tool. This is not the tool we're looking for, but two under that will be the blob brush tool and we're gonna click that. It looks similar to the brush tool but you'll notice it has like a blob and a rectangle attached to it. Very simple thing to recognize. So, once we click on it, I'm just gonna draw some shapes out on the art board and you'll notice that these shapes, they overlap They're not connected in way, shape, form or fashion. It stacks like any other shape in Illustrator. But if we double click and we open the blob brush options and we click, 'keep selected' and 'merge only with selection' and we take that off, click OK. Once we draw over it, it now joins with the selected but still maintains the shape of the one behind. Now if we go back into our options and we turn 'keep selected' off, click okay. Once we do it now, all of these items become intertwined. Now in our blob brush panel, we have fidelity and smoothness. Now with fidelity and smoothness, the higher we go with fidelity and our smoothness, the more rounded our shapes will be in terms of us painting. This will reduce the number of anchor points that are actually on the shape and because of that it uses less information in Illustrator. So it's a good thing. When you reduce it, it becomes more accurate but it adds more anchor points. And the more anchor points Illustrator has the more information it's going to process per shape.

Down at the bottom of our window you'll notice we have size, angle and roundness. Our size panel, once we slide the slider, you'll notice, it changes the size of our brush and that'll be the default size that we use once we click OK and we head back to our art board. The angle will change according to what we put here and that will be a default angle. And our roundness, it pinches and expands so that we can change how round our brush is gonna be. Now on the right of those, we have options under the size, angle and roundness panel. These allow us to change how they are affected as we are brushing. We have fixed, random, pressure, stylus wheel, tilt, bearing and rotation.

Depending upon whether or not it's random it'll, as you're moving a brush along the size will actually change at a random interval. If it's set to fixed, it will stay whatever your middle size is and it will not change at all. It will always stay that size. If you go to pressure, stylus will tilt bearing or rotation. It will all change varying on how your actually rotating, tilting, the amount of pressure you're putting down on your art board or on your tablet and then you'll get different settings according to that.

Now when this isn't set to fixed, you'll notice that a third option opens up and that is variation. In the variation panel you can change the variation between your brush sizes, angle and roundness. So you can decrease it so that there's less variation or you can increase it and you'll the sizes change in your panel. So if this was at random right now and I drew on the board, it will give me random sizes. Or if I have pressure, using my tablet, then depending upon how much pressure I apply, the line will become thicker or less thick, really, really thin, depending on how hard I'm going to press down. So right now we're gonna put it at random, click OK. All right, I'll leave it like this and that is how you use the blob brush in Adobe Illustrator.

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