I have the same problem as I have two Brother MFC-J6510DW inkjets and an MFC-J6520DW and I want to be able to print to them. But they are also a long way from where I use the Pi. All the open source drivers for Brother seem to be for Laser Printers.
I could simply print across the LAN or WLAN, but I want to avoid that. Not for any specific reason other than that I'm curious.
So in case I can't find a USB printer driver solution, there is one fairly easy option if it works.
I can send the file from my Pi to one of my Android phones or tablets. In fact I can simply dedicate an old Android phone that is no longer being used, to be a print server.
I have already used 'Brother iPrint&Scan', which is available on Google Play Store to print from my Android phones over WiFi without having to resort to LAN. All my Brother inkjets have Wireless. None are actually connected to the network, so the Raspberry Pi would have to be communicating directly with the Android device, which then communicates directly with the printer.
I haven't actually tried this yet, but with built in wireless and bluetooth in the new Pi 3 I should be able to simply do a bluetooth file transfer to the Android device and a print from there over Wireless to the Brother printer.
If somebody else beats me to testing it, please let me know if it worked well. Otherwise, once I get around to enabling Bluetooth on the Pi 3 I will try it myself and post.
Hopefully, with so many of us having old Android phones leftover after an upgrade, this might provide a very simply solution. And of course, there are similar Android apps for other brands of printer with built in Wireless.
https://play.google.com/store/apps/deta ... rint&hl=en
Brother iPrint&Scan is a free app that lets you print from and scan to your Android device. Use your local wireless network to connect your Android device to your Brother printer or all-in-one. Some new advanced functions have been added (edit, fax send, fax preview, copy preview, machine status). For a list of supported models, please visit your local Brother website.