There are limits to the amount able to be used for each rank.
There are limits to how many Ginto tubes a Quincy can take with him based on rank. IE a rank 1 Quincy (the first rank when they're allowed to even carry the things) Can carry 3.
So, lets say.
Rank 1. 3
Rank 2. 5
Rank 3. 8
Rank 4. 10
Rank 6. 10
Rank 6. 12
Rank 7. 12
Rank 8 12
Rank 9 12
Rank 10. 14
Rank 11. I would figure an unlimited amount as long as preparation is taken, after all, there is only one rank 11 person for that race.
Without preparation, 16.
The more Ginto tubes required, the stronger the tech will be
Not necessarily. Ginto can be used as a catalyst for more powerful techniques as they are simply tubes that carry Reiryoku or Reishi. So, while a low level weaker technique may take 2 Ginto, a higher level stronger technique would only take 1.
The explanation is that stronger Ginto are going to need a portion of your own Reiryoku, or they need preparation to form/create. OR! They are simply harder to create/perform but mainly, control.
Ok, and for applications, it will go a little something like this.
First, someone will create the Ginto with the template. Then, someone puts up a training app of a similar length to an equivalent strength Kidou.
rank of ginto x 100 + 100.