Going by the chart I just checked, both Imation +R and -R and made by Ricoh who also makes Ritek. They should be a good choice unless they recently changed the manufacturer they buy from and the chart isn't right. I think they are still Ricoh.
Jerry
I've not tried Imation DVD's, but, their CD's didn't last very long in my experience. Unreadable discs within a year. I used to use them, but, not anymore.