History of the tarot spread?

HeidiLynn

I have used a lot of different spreads in the last 4 years. Something I have not been able to find in all my study and reading on the subject though is the history of the spread itself.

I personally prefer to use linear spreads, either horizontal lines or verticle, but have used circular, the Celtic cross,etc.

Is there a reason, besides appearance that spreads aren't all linear? How did they become shaped?