How to Create an Annotation in Photoshop on Mac — From the New Document menu, select New > Markup or Edit > Edit in Photoshop, or go to a document that has already been created. In Photoshop, choose Edit > Add > Annotation. In the dialog that pops up, click to select both the shape and the image, and then click the Mask button in the toolbar. See my Tutorials on creating Annotation for Mac using Adobe Illustrator on Mac — How to Create an Annotation Using a Photo — In the image to the left, the Photoshop is highlighted, as it includes the Quick Mask tool, and the image to the right of it is an InDesign, which does not include the Quick Mask tool. Once you have the two shapes defined and are ready to go, click the “Mask” button in the toolbar to select both. In the window appearing, click to the right of the Mask button and drag to the left. See the Pen Quick Mask Masking in Illustrator on Mac by Paul O'Hare (pothead) Use the Mask tool to get a quick, neat preview of what's going to be on your drawing — but be careful where it's used. It's not great for previewing large shapes. Here is what my mask looks like, applied as a mask to the image. The mask can be used as a rough outline of the shape, and it can cover up any mistakes you might make during the process. Just be sure to be careful where it gets applied. See the Pen Quick Mask Masking in Illustrator by Paul O'Hare — This tutorial will show you how to create a mask in one of the best applications on the Mac. It will be a quick way to preview an image, but be careful what you choose and make sure you are using it in the correct context, as otherwise it would not be very practical. See the Pen Masking in Apple Illustrator — I have added a green and orange marker to the mask to show how I use the tool. See the Pen Getting Started with Quick Mask in Apple Illustrator — Apple will tell you if your brushstroke mask does anything, and then you can use it by clicking on the little pencil icon in the bottom right and clicking in that area of the mask — it'll show the Brush in use, and the Brush stroke.