Print Time Scaling

Requester:  Terry, thanks for the prints you made that were twice as big.  How long should it take to get the rest of them?
Me: Well, the regular sized ones took 4 hours, so 16 for these.
Requester: You doubled the size, why not just twice the time?
Me: By doubling the length and width, it’s actually four times bigger.  So, it’ll take 40 minutes a page instead of 10.
Requester: But it’s only twice as big.
(This is what I was afraid of)
Me: When do you need these by?
Requester: Three days from now.
Me: How about I just give you a call when I have them done and I’ll work as fast as I can?
Requester: Now that’s what I wanted to hear.

And the silence after he hung up the phone was what I wanted to hear.