Step 1: I open my Keynote handout presentation. I select File/ Print. Keynote defaults to Keynote in drop down box - I select "Layout."
Step 2: In the "Pages Per Sheet" box, I choose 6. Note: This "Pages per Sheet" choice doesn't appear on the default "Keynote" print screen.
Step 3: I click "PDF" button in lower left and chose "Save as PDF" This gives me a color pdf - 6 slides per page. In the sample I'm working on, I have now created a 16 MB PDF file
Now my goal is to convert to gray scale and to reduce the file size.
Step 4: Open the newly created PDF handout in Apple Preview. I choose "File/Save As... "
In the "Quartz Filter" selection box, I choose "Gray Tone." I save that new gray tone PDF. Nice looking handout, but I have greatly increased the file size. (from 16 to 103 MB). Too big to send to the client!
Step 5: I open the newly created Gray Tone version of the pdf in Preview and do another "Save As..." Just like in step 4. This time in the "Quartz Filter" selection box, I choose "Reduce File Size." That creates a new PDF with file size reduced from 103 MB to 5.7 MB (Even smaller than 16 MB color PDF I created in step 3)
Not the most elegant solution if you are used to the ease of doing this in PowerPoint .
Hope this helps!