Texturing a painting helps bring life to your image. Just take a look at your surroundings; There are textures everywhere. With this tutorial, I'm going to show you how I go about texturing paintings. Keep in mind that this is not the only way to do this, but it should be a helpful read. Step 1. The first thing you need to do is decide what to texture, and take it's material into account. For this tutorial, I'm going to start with something simple; A wall, for example. The first thing we need to do, before even worrying about textures, is to define the form; The wall should be fully rendered.
Now come back to layers tab and select the Background Layer. Now goto Filter �> Render �> Lighting Effects Same settings Texture Channel : The new channel you've created (mostly Aplha 1) Height : 5
You can get textures from your digital camera or download from internet. But, in some cases, you need to tile them. This tutorial will show you how to create a seamless tileable texture using Photoshop. Then, you can use this texture to your 3D model or just apply as pattern in Photoshop. Definitely, this is a simple technique, but every 3D artist should know about it.