Best REEL TO REEL blank tape?

The reason I put some vinyl on R2R is because some albums only have a few good songs.
Take Adam Ant,I have the entire catalog but Stripped and Vive Le Rock only have a few good cuts so I put those on tape and put the albums in a box. When the box is full I take them down and cash them in for store credit. I’m thinning out the herd,I have close to 20,000 albums and I ain’t getting any younger. It’s a process...

If you're already going through the trouble of transferring your vinyl to tape, might as well get the best sound you can. As mentioned above, 15ips 2-track on 1/4 tape is about the best you can get. The sound of tape is second to none and there's a big difference in sound quality between 2-track and 4-track. If you've already purchased the RT-909 than 2-track wouldn't be an option.

scar972 
while what you say is absolutely true, I consider 15 IPS a waste of tape; that would only be for a live musical event. I can't tell the difference between 15 IPS and 7 1/2 IPS for CD's and LP's; but if the tape isn't a problem, why not?  And of course the machine has to be 2 track. 

If anyone stops to figure how much 15 IPS on 2 track is going to cost, as well as the shorter time for what they're getting, they might reconsider after they experiment.  But since this is theoretical, why not.

@qdrone those are precisely my reasons for making tapes. There are millions of us who have been doing it for decades. I've done ADC with good results (better than the commercial CDs) but still prefer tape for the sound. 

I'm still not all together clear on the best sources for new R2R tape purchases. Please help.