Hello. I have highlights at the top layers of my image that I want to "punch out" all the way to the bottom. In other words, if the background in blue, the highlights become blue. I read the thread on division on top of division and clipping was suggested. If I understand clipping correctly, you need to select the top item and the one below it that you want to punch out. or in division you essentially do the same thing.

My hangup is that I have three halftones stacked beneath the image. Selecting each of them will be a clicking nightmare. I cannot figure out how to select "everything from here down."

Is there an easy way to make an object "transparent" by essentially out out of everythin below it? Like the person shaped hole in the cartoon door?

The only thing that comes to mind is rather hackish, but it will work.

1. Select all of the highlights that you want to act this way. Set their fill to black, then group them (Ctrl-G).
2. Now press ! to Invert Selection, and group everything else in a separate group. Press End to lower this group to the bottom.
3. Make a huge rectangle that covers the entire picture. Set its fill to white. You can make it really huge, it doesn't matter if there is any overhang.
4. Press Page Down to lower the white rectangle below the black highlight group.
5. Keep the white rectangle selected, and select the black highlight group (Shift-Click). Group these.
6. Ctrl-A to select everything, which should just be two big groups: 1) the white rectangle and black highlight group, and 2) the everything-else group.
7. Go to Object -> Mask -> Set.

In the mask, the black highlights will punch holes through everything, and the white rectangle will let everything else show. You can still edit things fairly easily by selecting the everything-else group (just click on something), then press Ctrl-Enter to "enter" the group. Now Inkscape acts as if that group is the entire canvas, and you can select things and edit them like normal. To get out of the "group editing" mode, just double-click on a blank area.

If you need to edit the highlights, select the everything-else group and go to Object -> Mask -> Release. This will let you see the highlights again and change them. Remember they're in their own group, so you'll want to "enter" the highlight group to add things to it. Anything black will make a hole when you set the mask again.

Let me know if you have any questions, I realize this explanation may be a bit unclear.

Nope, it isn't unclear at all. Thanks for the help. At least I wasn't overlooking a simple button.