Most of the time an image needs to remove its background. For this change, a lot of techniques are needed to be applied. Different pictures require different types of methods. Channel masking is a little complex way of image editing. For example, when we need to mask out hair or furry areas of an image, it becomes a very difficult work and selecting those areas with brush strokes are time consuming also. If the object of the picture has contrast in a sufficient amount, then the channel masking procedure will be very easy to apply. In details, we use the channel palate to see which channel displays the most contrast for working with this method. As such, if it is a blue channel, we create a duplicate copy of that channel and apply level on that to increase the contrast sufficiently. We can also paint over the inner portion of the new channel with black color for making it completely black, if it is necessary. Then we can inverse it to make the black to white or white to black. After that we have to copy the channel and paste it on the layer tab to make a new layer. That is how we can make a mask and put it on a portion of a photo like a layer. Well it is absolutely safe to make a copy of a layer.