Not sure about the 3880, but I'll assume the overspray from borderless printing is handle in a similar manner to the wide format Epson printers I have used for many years. If you look just above the paper deck you will notice a row of small "pads", some of which will eventually accumulate ink from borderless printing. You will also notice that the only pads that do accumulate ink are those related to the roll sizes set for borderless printing in the Epson driver. There are a lot of pads other than those at the borderless roll paper interval and they are essentially extra pads that can be used when the borderless pads become over saturated with ink. Simply remove the saturated pad and replace with a clean one. Behind the "extra" pads is a solid panel, while behind the overspray pads there is an opening through which the ink flows to the maintenance tank. I find that occasionally a lint free paper towel will absorb some of the ink on the pad and keep it in good shape for a long time. The pad at the right end of the row will accumulate the most ink and should probably be cleaned slightly or replaced at a more frequent interval. That will assure no problems with the print head possibly picking up some of that ink and depositing it on the paper. A rather unlikely occurrence, but definitely possible. For the most part it's a print and forget about it scenario, since this seems to be a maintenance-free area on these printers.
Gary
