Masking 101
Ever wanted to have an image within an image? Lets say you have a background image of something, yet you want a certain part of another picture to peek through it. You could easily cut part of the picture and paste, however masking gives you the benefit of moving around the image underneath, and re-aligning the “portal” that you are looking into.
First Step: Define the background image
Open an image that you want to use:
Second Step: Draw a portal. You can use just about any shape tool to do this and use a color that is easy to see against the background image. I will use the circle and select yellow as the color.
Third Step: Add another picture to the file. Choose another picture that you want to use. make sure it is larger than the portal, however smaller than the background. I recommend opening the image, resizing it to something smaller than the original background, then either copying the whole image onto the background or dragging it to the background image. You can easily re-size the image by pressing CTRL T and then while holding SHIFT, dragging the image. I would only recommend reducing. If you need enlarge it there may be pixelation.
Step 4: Applying the Clipping Mask. Open your Layers pallet. You should have 3 layers, one for the background image, 2 for the circle, and 3 for the overlaying image. Make sure that the top image is a layer above the shape, in our case the yellow circle. Right click on the top layer (the image) in the layers palette and select Create Clipping Mask.
Step 4: Save your file to whatever format you want, however make sure to keep a PhotoShop source file saved! If your image is not in the correct position, now worries, you can easily move either the masked image or the circle to your specifics. This is a lot easier than cutting and pasting. You can also adjust the size of your shape as well if it is too large or small.
Good luck masking!
