Hi Deanna,
I looked into the issue you reported with respect to your entry of 21" x 15" changing to 21" and I was able to reproduce that problem. It appears that our system isn't handling the quotation marks well but I was able to enter 21 Inch x 15 Inch and 21 x 15 Inch successfully so perhaps something similar would work for you.
I was also able to confirm that the quotation mark symbol is accepted in variation values when listing directly through eBay so I have passed the details of this issue over to our developers to see if we can get our system adjusted to accept quotation marks.
While it is possible to enter 2 more than one custom attribute, the process is currently a bit tricky if you are listing in a category that only displays one Custom option by default. If you are listing in such a category, you would need to do the following to use 2 Custom attributes:
1) Use the Variation Generator to create your first Custom attribute
2) Click the “Generate Variations” button and your variations will be created
3) Click the “Variation Generator” button again and you should then see the first Custom attribute you created on the list as well as a new Custom Attribute option that you can use to create the second one
This shortcoming of our Multi Variation interface was just brought to our attention today and we will be working adjusting the interface to allow for multiple Custom attributes to be used in this category much more gracefully for a future site update.
The issue you mentioned with respect to the preview is expected behavior, but your listings will still show the drop down menus for each attribute that your perspective buyers can select from when the listings post to eBay – just like any other multi variation listings you may see on eBay.
I hope this helps. If you need any further assistance with this, please feel free to contact our customer support team using the “File a Support Request” button on our “Help” page.
-Mike