When i started wit my first Festoy sander, i got several different grits in progression starting with 80 grit up to 180. The problem i discovered was that i did not get the progression in one type, such as Rubin. Each step up was a different type and I was running into somewhat non satisfaction with my progressions, especially in the lower grades.
By the time i was wearing out packages (I got everything for the 150 in 5 and 10 packs.), I was beginning to understand a little more about what each grade and grit was good for. My biggest problem was with Rubin. That seemed to not cut wood as well as elected in the lower grits and it did not seem to last as long as i had hoped. Once i found grant, I discovered that the RO 150 was a much better sander that i had even dreamed of. I now have Granat in grits starting at 40, progressing by steps 0f 20 grits up to 100.
In the past, i found I used a lot more paper in the lower grits as I was sort of getting inpatient until I got to the higher grits. I now go thru the steps with Granat in much less time, far less impatience and a disc seems to last forever. By the time i get to the higher grits, I am even using less paper there as the ground work has gone a lot smoother. I am able to use up my old stocks of Rubin with better results.
I am currently working on a serving tray for THE BOSS while she is away on other side of the big pond. I sanded the whole tray starting with 60 grit Grant. actually, i started with 60 grit Rubin and was starting to get impatient. I was only doing the sides and using the Festoy sanding block that is configured to use a full 150 disc. I was trying to get rid of saw marks. I had used Bandsaw to rip two of the sides. They were dead on straight, but with tooth marks. I finally changed over to a disc of Granat 60 and wow! what a difference. I had intended to use my LS 130, but those marks disappeared so fast doing by hand, i never did take the 130 out of its systainer. Once those tooth marks were gone, the higher grits were easy and fast no matter which type of paper I used.