Simulating traditional painting with the iPad

A major reason why digital artwork can look overly clean and smooth is the tendency to start painting on a perfectly flat white background. When painting with genuine oils, acrylics, and watercolors you'd likely work on a canvas, board, or paper. All of these have a textured surface that although subtle, remain visible as you apply paint.

The ArtRage iPad app solves this problem in digital art by offering a range of surface textures to choose from when you start your painting. You can specify the paper or canvas type, and even determine how rough or visible the texture grain is.

An alternative method for creating a surface texture in other apps, such as Procreate (pictured here) is to import a photographic texture and use blend modes to work on top of it. To do this, you will need to find a royalty-free texture image on the Web or photograph your own. Then, import this texture into your app as a layer. Once imported, create a new layer above the texture and apply the Multiply blend mode. Ideally, the texture that you choose will be bright, otherwise it will be difficult to see the brush strokes that you are adding. You may also want to experiment with different blend modes to combine your painting with the texture in more interesting ways.

The second important consideration for simulating real-world painting on the iPad is the brush that you choose to paint with. When observing oil paintings up close, you can usually see the brush strokes applied by the artist, but this is a lot less common with digital painting. The main reason is that digital artists typically work with smooth brushes that are more airbrush-like. These produce more evenly blended paintings. Therefore it is important to choose digital brush shapes in your app that will define bristles like a traditional brush. In this slide, I used SketchBook Pro for iPad as an example.

Another big issue is how to effectively blend colors together. The reason that blending can be difficult to achieve digitally is that it isnʼt something that happens automatically in most apps. With real paint, blending is much easier because of the liquid quality of paint.

There are a few ways to achieve blending in your chosen app. First, you can use the opacity level of your paint to gradually paint colors on top of each other. This method works in any app and is my main method for blending colors. A second method, which is available in a couple of apps, including Lucky Clan's ArtStudio for iPad, is to use a wet blending or smudge tool. This allows you to smudge the colors on your canvas into each other as though the entire painting were wet. This can be a very quick and effective way of blending if used in moderation. Often the smudge tool is overused, which can result in streaks of color and overly smooth looking paintings.

A more sophisticated way of reproducing the liquid quality of paint is to use the ArtRage app, which has a broad selection of tools designed specifically for simulating traditional painting techniques. For oil painting, you can choose to digitally squeeze tubes of paint directly onto the canvas, use a palette knife to spread the paint, or even use a paint brush to apply precise brush strokes.

The oil painting brush has a number of variables that give you incredible control over the strokes you make on the canvas. You can specify the size of the brush, the pressure of the brush strokes applied, how much thinner you would use to dilute the paint, and how much paint you want to load onto the brush for each stroke. There are also a few check boxes to make the paint automatically dry after each stroke, clean the brush automatically, and to choose between a stiff square brush or a softer rounded head.

Watercolor is one of the hardest paint media to reproduce digitally because it is a very unpredictable and natural style of art. Not only are you working with water-based translucent colors, but there is a fluid natural blending that is difficult to simulate. That said, ArtRage offers an impressive solution to this problem with a configurable watercolor brush. Similar to the oil brush, there are settings to define whether the paper is wet and to what degree the colors can blend.

Another application that attempts to simulate water based paint is Adobeʼs Eazel app. Despite having fewer variables than ArtRage, Adobe Eazel gives you a similar environment watercolor in which colors naturally bleed into each other with a realistic time-based drying method.