I assume that you want to do this for your archive pages. I'll use Individual archives as an example but you can do this for the other archive types as well.
Go to Templates and in the archive templates area click the link to create a new template. Give it a name like "Printable Individual Archive" and paste in your desired template.
Next, go to Weblog Config | Archiving. Click the link to add a new archive type to the list. Select your "Printable Individual Archive" template and associate it with the Individual archive type.
Now you need to come up with a unique filename for it, using the archive file template field. You might do something like this:
CODE
<$MTEntryCategory dirify="1">/<$MTEntryID pad="1"$>-print.html
This will place each page in a directory named for the entry's category then give it a filename like 000100-print.html
When you're done, rebuild your site to create the new archive files.
To link to them, you will need to "handcode" the link, for instance:
CODE
<a href="<$MTBlogArchiveURL$><$MTEntryCategory dirify="1"$>/<$MTEntryID pad="1"$>-print.html">Printable version</a>