Opacity vs Flow
“Opacity” and “flow” are basically English Language words, but in this article we will be discussing the difference between the opacity and flow of “brush tools” used for Photoshop or other digital graphic editor programs for sketching and painting tools available today for digital creativity. The brush tools are the main or the most fundamental tools for any digital graphic editor program as well as any painting and sketching program. The brush tools are basic tools which are necessary for adding, changing, or removing anything. The two most important characteristics of brush tools are their opacity and flow.
Opacity and flow are illustrated on the brush menu as numerical percentages. The opacity and flow of the brush can be changed in its percentage. It can either be increased or decreased. A slider appears when we click on the brush tool, and the slider can be used to control the opacity and the flow of the brush as per the requirements.
Opacity
Opacity basically controls the intensity of any color chosen. It refers to how much base layer is visible after the color is applied. If the opacity is 0%, then the base layer is completely visible. The brush does not leave any mark, and the color layer is transparent or see through. If the opacity is 100%, then the base layer is not visible at all. As the meaning of the word suggests, it is opaque. That is, it is neither translucent nor transparent. It is impenetrable to light. Opacity is for the pressure of the brush tool; the pressure can be controlled by it. The opacity of the color if set at 50%, will not let the density of the color increase no matter how many strokes of color you use.
Flow
Flow basically controls the dispersion of color. It refers to the rate at which the color is being dispersed. When the brush is depressed, the density (opacity) of the color increases as per the rate set by the flow characteristic until the required opacity is achieved. If the percentage of flow is less, the flow from the brush is slow, and the brush image will be more sporadic. If it is set at a higher percentage, then there is a continuous flow which makes the paint or color appear more even. For example, if the brush is set at 50% flow and 100% opacity, one stroke of the brush is required to get a 100% stroke which is filled. Whereas if the flow is 100% and the opacity at 50%, more than one stroke is required to fill the area. In simpler words, we can say the flow is the amount of paint dispersed per stroke until full opacity is reached.
Summary:
Opacity basically controls the intensity of any color chosen; flow basically controls the dispersion of color or the rate of color dispersion.