Opacity or Flow?

[DWThomp]

I use CS2 and have a question on using any type of brush. I usually have the brush opacity set to 100% and flow to anywhere from 2-10% for control. A lot of the tutorials I've read say use a low opacity, but never mention the flow. Would it be better to set the opacity to 2-10% and flow to 100% or does it matter?

Thanks in advance,
Dennis

[Doug Nelson]

Different strokes, of course, but opacity is much more predictable (for me) than flow. Flow will vary the opacity depending upon your stroke speed.

Try this experiment:

Pick a dark non-black color and a large hard round brush on a white document. Set opacity to 10% and flow to 100% and slowly draw a single line across the top, varying the speed a little but never letting up on the mouse button.

Now repeat on the bottom, only reverse the opacity and flow numbers. When I do this, I get a smooth line at the top and a lumpy mess at the bottom.

Of course, if you get better results using flow, more power to you. Whatever works for you is the best technique.

[Syd]

Doug's advice is spot on. Do the experiment and you will see for yourself the difference. I asked exactly the same question not so long ago and Murray gave the FOLLOWING excellent advice.

Sincerely syd

[DWThomp]

Interesting experiment and I see what you mean, it almost looks like it was created by a spiralograph (if you remember one of these ). I also tried with a large soft brush, which is the one I use the most, and didn't notice the same type pattern. With a 10-flow/100-opacity I can keep the mouse button down and go back over to build the color up. With 100-flow/10-opacity you have to release the mouse button each time to build the color up.

It also looks like it starts out a lot lighter with the lower opacity. I guess it might depend on what brush you're using and the purpose as to which you'd use. Here is a small jpg with the results, tho don't know if you can tell much.

Thanks Doug & Syd for your replies.

Dennis

[BillFrey]

The 'spiral' looking effect is because PS's default Spacing is 25%, I almost always use <5% for a smooth brush.

Try the test again again moving the spacing lower and you'll see the difference.