WHAT DOES THE FLOW SLIDER IN THE OPTIONS BAR DO?
One thing I have been learning about while taking my “painting” journey is how brushes work and what changing the the different settings for my brushes will do, including an often overlooked slider – the Flow slider in the Options Bar. For this blog I am using one of my favorite painting brushes, Adobe’s Charcoal Brush 60 which I changed slightly by adding in the Shape Dynamics section of the Brush Panel an Angle Jitter of 19% to get a different stroke each time it was tapped. The image above was created using just this brush as both a regular brush and a Mixer Brush. For more info on this image, see Image 1 at end of blog.
Here is the technical definition. I like how an old Adobe Focus Guide on Brushes and Painting said “The Flow setting determines how quickly and smoothly the paint is applied. Brush strokes are made up of a number of points running together in a line. However, if you reduce the Flow, these points are painted less frequently, and the opacity of each is also reduced by the specified percentage.” Adobe’s manual defines the Flow as: “….sets the rate at which color is applied as you move the pointer over an area. As you paint over an area, keeping the mouse button down, the amount of color builds up based on the flow rate, up to the opacity setting. For example, if you set the opacity to 33% and the flow to 33%, each time you move over an area, its color moves 33% toward the brush color. The total will not exceed 33% opacity unless you release the mouse button and stroke over the area again.” The charts demonstrate this.
What I think is most significant is what the edges of your brush creates at the different flow rates. The Chalk brush was used for the chart examples, which has a very rough edge to it. Below is a chart using the regular brush and Options Bar settings of Opacity at 100% and Flows of 100% and 20%. You can see how the edges of the glide strokes change when the Flow is changed. When used as a dab stroke, it almost looks like a lower setting for the brush or layer opacity was used. Very different effects. Below is another chart that shows the same brush set to a brush Opacity of 30% and Flows of 100% and 20%.
In this case, you can start to see more variation. With the Opacity and Flow set low, you can hardly see the brush dab and the edges of the glide stroke are very soft and subtle. With the Flow at 100%, the glide stroke looks very reminiscent of a watercolor brush. Try using these settings with different brushes – with a soft round brush you get very different edges. Notice how much more control you have over the brush at a lower Flow rate, which is not necessarily the look you want. Take a minute and try this out yourself – it’s pretty interesting.
Many digital artists find that by varying the flow of their brushes, they can get a greater control over the strokes and achieve effects that might not have seemed possible without this adjustment. I think you can see that if you try the different flow settings. Harold Davis in his Photoshop Darkroom books says that if you are using a mouse and not a tablet, set the Flow to 50% so that you have a little more control over your strokes. Aaron Nace changes the Flow of his brushes all the time when he is retouching an image. For painting effects, I am now setting the Flow to 50% to start and if it takes too long to add the color/paint, then I set the flow higher. A low opacity with a low flow is often used to smooth out skin.
Flow shortcut keys apply to these tools: regular Brush Tool, Clone Stamp Tool, Eraser Tool, History Brush, Sponge Tool, and Mixer Brush Tool. Select Tool and press any number key to get the tool opacity to change to that percent. For example, 3 = 30%; 0 = 100%; 4 plus five quick taps = 45%. Note that for Mixer Brushes the Wet amount changes with these numbers. To change the Flow, press SHIFT+number key as above. I found this tip is important: If the AIRBRUSH ICON is turned on, omit the SHIFT key for Flow – this tool’s opacity is controlled by Pen Pressure. I have gotten really confused and set the brush opacities wrong because the Airbrush icon was turned on (it is located right after the Flow field in the Options Bar).
Martin Evening explains how the Flow works in the Mixer Brush. With a low Load amount and a high Flow amount, the paint flows out quickly and in shorter paint strokes; set to a low Flow amount results in longer less opaque strokes. This can create a significantly different effect in your painting. By the way, it is not good to use a Mixer Brush in a layer mask – they do not always give the desired effect. Change the brush back to a regular brush, and use the same brush. Almost all regular brushes can be used as a Mixer Brushes and vice versa – just need to save the brush so it appears in the Brush Preset panel. Then you have access for all brush types. Below is another image that used the Chalk brush discussed above. For more info, see Image 2 at end of blog.
Since this was a setting I was confused about, maybe this has helped some of you understand what the Flow is actually doing in an image. If painting is something you like to do in Photoshop, it is important to keep an eye on this slider and try different values. I always save my brushes as a Tool Preset (click the far left arrow and click New Preset icon to save) since just saving a Brush Preset does not save your Options Bar settings. Then you will always have your favorite settings available for your brush. Try experimenting with this slider and see if you like some of the different results……Digital Lady Syd
1. This image was taken in the grocery store of some yellow daisies. Just basic changes in Lightroom were done and once in Photoshop, Topaz (for website link see sidebar in my Tidbits Blog) Detail 3 was applied to sharpen up the flower petals and center. Painted Textures Thanksgiving Foliage texture was applied and the flower painted back in a layer mask. Originally I thought it would be nice as in the falls colors since the daisy was yellow. A Hue/Saturation Adjustment Layer was added and that is when the colors got switched over to the purples and blues. A Curves Adjustment Layer was applied to add back some contrast. The on a composite or stamped layer (CTRL+SHIFT+ALT+E) on top, the Camera Raw Filter was opened and a vignette created to focus on the flower more. Then Nik’s Analog Efex Pro was used and it actually brightened up the whole image – even a white vignette effect was put around the edge in the plug-in. Some paint clean up was done and a little touch of pink painted into the flower petals. That was it!
2. This is another image taken with my phone at the grocery. This time Painted Textures Bowl of Roses Canvas was used as a backdrop and the Old Design Shop’s French Label Eau De Lavande2 was added to it. Image was taken into Topaz ReStyle and more pinks were added into the image. A white Solid Color Fill Adjustment Layer was added and set to Color blend mode at 65% layer opacity. Camera Raw Filter’s Radial Filter was used to emphasize the flower pot. Some clean up and a Field Blur filter set to 20 pixels was applied. In the mask, a gradient was used so just the French saying and not the flower pot was slightly blurred. Last step was a Levels Adjustment Layer to add back some contrast.
Digital Lady Syd Related Blogs:
How to Turn a Brush into a Watercolor Brush
Learning How to Paint in Photoshop
Create a Winter Scene with Photoshop Brushes and Textures
Adobe Photoshop CS5′s Mixer Brushes