Hello
See the attached pic. i want to clip the blue rectangles from the black shape underneath.
Whenever I do it, it just leaves me with the opposite of what i want i.e. lots of black rectangles.

The blue rectangles are all grouped together into one object and they are z-positioned above the black shape.

Any help appreciated.

Hi.

With clipping you can define the area visible with a compound path.
That means, instead of grouping the blue paths together, draw a compound path with them that covers the desired area.
Like, combine the blue rectangles together and subtract it (Ctrl+-) from a rectangle below.

Other than that, maybe subtracting the blue rectangles from the shape below could be a solution too -if it was only one path filled with gray.

Unfortunately SVG has no notion of an "inverse" clipping path (it was proposed again for SVG2, but unfortunately dismissed, so it's not likely to happen in the near future, either). So as Lazur said, you need to create an "inverse" path yourself. I covered exactly this in part 13 of my tutorial series: viewtopic.php?f=6&t=11981

Doesn't it work to simply ungroup the blue rectangles, then select all blue rectangles and the black shape, and do Path -> Exclusion?

I just did a simple test:
- draw a black rectangle
- draw a few small blue rectangles on top of it
- select everything, do Path -> Exclusion
Remains the black shape with holes where the blue rectangles were. Isn't that the idea? Or didn't I get it?