Epson offers what appears to be the print drivers, including wireless connect,for the wf-3640 printer. (got it on sale from tigerrdirect.com retail shutdown) Although all but iscan install saying it need epkowa commponent. I must admit I am lost. I am convinced this printer can be setup to work with Ubuntu but I am at the point I need some help/guidance on what to do???? Even after installing all but iscan there is not printer that appears to be installed.
As far as I know, epkowa is the proprietary scanner driver by Epson. If it says you need the epkowa component (i.e. sane-epkowa back-end), that likely means you need to follow the below guides: How to install printer component/driver: http://tutorialforlinux.com/2014/08/23/how-to-install-epson-wf-3640-all-in-one-printer-drivers-quick-start-scanning-on-ubuntu-14-04-trusty-linux-easy-guide/ How to install scanner component/driver: http://tutorialforlinux.com/2014/08/23/quick-start-with-epson-scanner-for-ubuntu-14-04-trusty-lts-with-iscan-easy-guide/ Hope I was helpful :-)
A very late addition - hopefully somebody will benefit from this.
Above procedure (sudo apt-get install printer-driver-escpr, then add a printer in GUI) will result in a working printer, however it will not report ink levels, as it seems to create an IPP printer.
If you create a 2nd driver based on URI, enter "dnssd://EPSON%20WF-3640%20Series._ipp._tcp.local/" this will have the same functionality PLUS be able to report ink levels.