Depending on how many blanks you are talking about, I suggest you stack them in rows on 4 or 5 blanks (depending on their length) in a cross orientation to each row and 10 or so rows high.
Ideally, you could use something to strap tight the "tower", 2 straps on 2 opposite sides or use a heavy brick or something of that nature to put some weight down.
I will be important to store these towers in a protected and well-ventilated area, drying time very from woods types to the weather temps you experience in your area, in average 12 months is sufficient to some woods, others more dense woods will require about double that time.
Good luck...!
Cheers
George
