https://www.skillshare.com/classes/Marble-Repeating-Patterns-in-Photoshop-A-Photoshop-for-Lunch%E2%84%A2-Class/1300364066

Learn to make Marble in Photoshop. You will learn to make a basic marble design and how to turn that into a seamless repeating patterns. I will show you everything, step by step. You will learn techniques for filling in areas of a design using masks and also the Clone Stamp tool. You will see how to recolor the marble and how to extract some of the veins in the marble and color those in another color. This class is jam packed with detailed explanations of what every tool and effect does so that you will learn techniques you can apply to other images and in other circumstances in addition to making marble. 

By the end of this class you will have a range of different marble designs ready for use and which you can package as digital assets for sale or online distribution.