Epson WorkForce Pro WF-C5890 Wireless Color MFP Inkjet Printer - Manual (Page 186)

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You see this window:
2. Select the Document Source setting that matches where you placed your original, or select Auto
Detect to have Epson Scan 2 automatically detect the source.
3. Select the Scanning Side setting if you are scanning from the ADF.
4. Select the Document Size setting that matches the size of your original. You can select Customize
to enter a custom size, if necessary.