How to create clipping paths in Adobe Photoshop CS6

If you want to create a beautiful silhouette in Adobe Photoshop CS6 that translates well to text wrapping in other applications, create a clipping path. A clipping path is essentially a vector path that is transparent, part of the image is visible, and which part defines what. Typically, a path is created around an object that you want to silhouette.

1 Use the crayon tool to create a path around the image area that will become the silhouette.

2 In the Paths panel, select Save Path from the panel menu (click the triangle in the top right corner of the window), and then name the path. If Save Path is not visible, your path has already been saved - skip to step

3. From the same panel menu clipping path.

4. In the Clipping Path dialog box, choose your path from the drop-down list, if it is not already selected- click. Leave the flatness device pixel text box empty if you need to change it. The flatness value determines how many device pixels your silhouette will use to create. The higher the amount, the fewer points are created, thereby allowing for faster processing time.

This speed comes at a cost, but: If you set the flatness value too high, you can see (if you see nearby) straight edges instead of curved edges

5. Select File Save As and from the Format drop-down list, select Photoshop EPS in the EPS Options dialog box that displays the default settings, and click OK.

If you see Postscript errors while printing, select Path from the Clipping panel menu and increase the value to 2 pixels in the Flatness Pixel text box. Keep returning to this text box and increasing the value until the file prints or give up and try to print the document on another printer.

If you are placing this file in other Adobe applications, such as InDesign, you don't need to save the file to EPS- you can leave it as Photoshop

Create a path around the element you want to keep when you create the image clipping service
Make sure that you work on one level and not on the background level. To convert the background to a layer, hold down Alt (Windows) or Option (Mac) and double-click the background layer. The background layer is now 0 layer. In the Layers panel, click the Add Layer Mask button, and then click the Add Layer Mask again.

you may know more https://en.wikipedia.org/wiki/Clipping_path