Sketch-app: How do I edit an existing image mask?

Question

I can mask an image in Sketch by selecting the image and then clicking the "mask" button. I then have the ability to define the shape of the masking object. After the image is masked, if I double click the image I have the ability to edit the image inside the mask: resizing it, etc.

But how do I edit the shape masking the image, after the mask has already been applied? If I try to click the invisible shape masking the image, and resize it, nothing seems to happen (often the program thinks I want to select whatever object exists under the one I'm trying to edit). Every once in a while, I can successfully select the masking shape to resize it, but there doesn't seem to be any consistency with that ability and I have no idea how I trigger it.

Thanks!!

Answer 1

When you select the masked image in sketch, the corresponding layers group will be selected in the layers panel. Expand the layers folder containing the image and its masking object. Click on the layer representing the masking object. The masking object is now selected and you can resize it as needed.

Note: when hovering over the layer representing the masking object, an eye icon appears. If you click it, the resize / transform handles associated with the masking object disappear from view and you can no longer edit the masking object. Make sure the eye is not clicked (and if it is, click it again to disable it).