Basically we have to take Sawgrass' word that their patents mean what they claim they mean, unless we have the cash to challenge them in court. So the '907 patent may expire later this year, but they could easily claim one of their other patents is being breached by xxxxxxx selling sublimation inks, and we'd have to believe them.
The interesting thing to watch in September is what if anything the other ink manufacturers do when the '907 patent expires, although it will still be in their interests to keep the status quo.
Sawgrass must make a lot of money on sublimation ink sales, and aren't going to admit that their monopoly, neither would they admit that their patent isn't actually what they claim it is (if it wasn't) as it wouldn't be in their interests.