[xxSparkleSxx]

Could using printed fonts that look like hand-writing to advertise count as willful deception?

You're trying to trick the consumer into thinking a human made the sign (and by extension the product as well), which was actually made my machines.

I don't see a difference. When I buy a product, there is no disclosure of the manufacturing process.

I could only see a good lawyer losing this case if OP signed a contract that explicitly stated the process in which his work must be produced.

[jsjohnst]

In your scenario, I don't see a correlation with the facts you presented vs the previous example. In the previous example, they provided evidence of a potential (IANAL or a judge or on a jury for the case, thus potential) crime, I merely stated that I believed the willful deception would likely be a significant point in the case. Without knowing the "case" in your example, I can't know if the font used would be significant or not.