Is there anyway to add a cut (Read More) in a article?

[Akutenshi3]

I'm trying to add a cut on my articles at http://www.thevenuscave.com and have it where I specify. Right now I can only have the option to show the article in full (like the first one I have there) or have it just display a sentence and then have the cut (ones below). Anyone know if I can choose where to have it?

[Lynne]

Why not just use the Preview Break?

[Akutenshi3]

I've tried that and it doesn't work :( Still shows the entire content.