From your description it sounds like you are not familiar with 2-up printing ?

In the Print dialog you have the options 1-up, 2-up, and 4-up.

Hello Torrin,

I'm thinking "2-up printing" will not give you the results you are asking for. "2-up printing" will rotate your music, reduce your part to fit on the left half of a letter sized sheet in landscape orientation. It will not create a clone on the bottom half of the page in portrait orientation. Not what you want. Also - even if you choose to print multiple copies in 2-up mode, Finale will print multiple separate sheets of paper - all with a single copy of your desired part, rotated 90º and too small on the left side of the paper.

The only way I have figured out how to create a single letter sized page with two copies stacked vertically is to export the parts as PDF or JPG, then import them into a page layout program, then copying and pasting a duplicate for the bottom half of the page.  I use Indesign CS6 or Pages (Mac) - but any page layout software would work. Then, export the new page layout document as a PDF for emailing, printing/cutting/binding, etc.

Obviously, every time you make a change to your score in Finale - you would need to go through the entire process again - not the best.

One thing I have not tried, but have been wondering if it would work... would be to copy the measures of the score (in Finale) and paste it to the end of the original Finale document. Basically, creating two copies of the score back to back, with Finale seeing it as a single longer score. You would then just format your double parts as two copies of the same part - adding additional title text blocks as needed for the second (bottom) part. Then - print as usual.

This eliminates using the page layout program, but would require you to copy any edits from the first part to the duplicate at the end of the file. (That should be easy)

Also - consider downloading and installing the JW plug-In called "Copy Part Layout..." Just format your first part and then let the plug-in copy that format to all remaining parts.

This plug-in has saved me hours in formatting parts for pep band, etc.  The 64bit version works with Finale 25 and will clone your layout from one part to another. Here is a link: COPY PART LAYOUT.   In my browser, the plug-in is on page 2, part way down the page. (they are not listed alphabetically)
There are several plug-ins here that will save you hours of editing time. Good luck and let us know if you try the copy and paste idea and whether it works...

All good points.

Another thing to consider is that you can print to a .pdf the size of a virtual A9 envelope — these happen to be 8 1/2 x 5 1/2. Set this up as a custom size in the Print Menu so that you can call it up as needed.

You can then lay out your 2-up in Preview. It's not quite as easy as a few other applications but it does get the job done and it's free.

A number of Adobe products handle this easily but most are expensive and require subscription. Photoshop Elements is the exception and the easiest tool for this use by far. Bundled with Premier Elements, it's $99 but resellers might have it broken out for $69 less. 

http://www.adobe.com/products/photoshop-premiere-elements/features.html

https://www.amazon.com/Adobe-65273274-Photoshop-Elements-15/dp/B01KICI4LQ

Although I do have Elements 15, I still use Elements 6 for this task, custom layouts of .pdf files.

If you will attempt this in Word or Text, don't use .pdf files. Instead, save as .png or .jpeg. PDFs look terrible in Word documents.

I forgot the obvious. Forget 2-up. You can get A9 sized paper and just print to it.

Of course, you can also just chop Letter stock in half as it's the exact same size.

For certain things I do, I use A9 envelopes and stock. Unless I need fancy card stock, out comes the paper cutter and I make up a batch.

>(so that they can be sent, printed, and then cut.)<

Places I deal with can cut first — do go with what works best, though.

Maybe try these folks: 

https://www.papersource.com/envelopes/A9.html

Thank you for all of your suggestions! I ended up being able to solve the problem by creating a file with the Marching Band Setup (which prints parts to Octavo-sized pages.) I printed those parts from Finale to PDFs, and then I printed the parts in Preview. When I printed them in Preview, I used these settings:

Copies per page: 2

Scale to Fit

Print Entire Image

Portrait Orientation

This created the desired result. Thank you!

Torrin