Excel Spreadsheets as Proofs

Boy, were we surprised when we found out that Workfront can't add Excel documents as proofs. The recommended workaround was to "take screenshots."

When we upload an Excel document as a proof, it breaks the entire spreadsheet into 8.5x11 inch page parts, which scrambles the content. Another suggested workaround was to "set print area" of the sheet first, which correctly opens one sheet in a proof, but breaks any additional sheets in the Excel file, as above.

Surely we aren't the only team having this issue?