I'd bill per hour. But you have to remember to keep a clock/timer going. I seem to remember that Sams3d record times automatically every minute they spend on a project. I'n my business, bespoke stationary/graphic design, I agree a price with the client first before starting work. That works for both of us because I can never tell how much time I'm gonna spend on a particular job. Some guys charge for 'setting up' which I think is an excuse for a rip-off. My clients pay for the product he/she receives at the end of the project. The Bryster

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All the Woes of a World by Jonathan Icknield aka The Bryster

And in my final hours - I would cling rather to the tattooed hand of kindness - than the unblemished hand of hate...