How do I do this... re-paths

[michael_affeld@adobeforums.com]

I am sure that this is a simple task, and hopefully I can give an uncomplicated description of what I am trying to do. I have a complex rectangular vector item (a piece of artwork with many paths and sections) and what I am trying to do is create a logo only showing a half circle of this item by masking the outer section to, again- only show a half circle of this artwork. I started with creating a circle and cutting in in half by creating a section and using pathfinder/"minus back". So now I have my half circle placed, however here is the part I cannot seem to do. Instead of a horizontal line at the bottom of my half circle currently filled with none, I want to build onto and around the half circle and fill it with white so my result is just a half circle of my artwork showing. Everything I am trying to do to break into the original half circe path to bring points and lines outside of it are not working. What would be the most efficient way of doing this, if it makes sense? Also, will this white section over the artwork cause problems at the printer?
thank you for your input.

[michael_affeld@adobeforums.com]

Just a check.

[lee_vickers@adobeforums.com]

Clipping mask?

[jonf@adobeforums.com]

It sounds like you're describing a mask. Just put your half circle over the top of the other artwork and use the make mask command. That is the best way to accomplish what you want.

However to answer your secondary question, if you wanted to end up with a white box with the circle knocked out of it to place over the top of your artwork, you could just use the minus front pathfinder again. Make a white box. Place the half circle in front of it, select both, and use minus front. Or select both and make a compound path.

But use a mask for the current problem!

[michael_affeld@adobeforums.com]

Thanks for the input. The mask worked fine and accomplished my goals, but then i played around more in pathfinder, and the crop function did the trick. That leaves me with two more questions... 1.) with a project similar to my original question... why would you even mess with masks, why not just "crop" it all of the time, and save any possibilities of the mask being "messed-up" somewhere down the line. 2.) Just to learn something about paths... going back to my original question, how would I build onto the half circle like I originally was trying to do?
Thanks again.

[jonf@adobeforums.com]

The mask is editable. If you want to adjust position later it leaves you the option. And crop won't always work exactly like you'd expect on vector objects if you have open paths, for instance.

From what I thnk I understand of your description, you can't build onto a closed path. You need to create a separate closed path then unite them using the compound path command, or some pathfinder function. You can cut the original object with a the knife tool, or delete a section of path between two points, if you need to re-open the path to add onto the drawing. But that won't accomplish anything approaching a knocked out window.

[Scott_Weichert@adobeforums.com]

You can also simply use the add node pen tool to add points to your circle path and alter them.

[michael_affeld@adobeforums.com]

Thanks for your input, I'll be playing around more in Ai to learn. I guess my weakest point right now is what the printer prefers. (actually, because most of them differ in some aspects I will re-word that to... what most printers prefer.)
thanks again