fGeorge wrote:

Thing is if you'd have used a bit of logic first&formost you would ve saved
the penny's ie two 3mm thick perspex sheets drilled at 4 corners and cut to
size.

You've never done that, have you?

The Logo could have been printed out and laminated then sandwiched between
the two sheets of perspex and sign changed at any time during the course of
the buisness.

Uh huh, you've definitely never tried it. I have.

It's incredibly expensive because you have to buy a full sheet of
acrylic even if you only use an A3 sized piece. So unless you're making
several signs there's a lot of waste, which is going to cost a lot more
than plywood.

There's no weather proofing in what you suggest, water gets between the
sheets, and even if the laminating is better than usual, the moisture
condenses and makes the sign unreadable.

The use of only four fixing points at the corners is inadequate and the
probability is that the pressure of tightening up the fixings will cause
the acrylic to crack. Acrylic has a lot of internal stress and cracks
easily. Even if it does not crack while being worked it will crack over
time, and it will crack and yellow very quickly in sunlight.

It's slightly better to use an acrylic front and an aluminium back, but
mostly what you're suggesting is no better than simply using a laminated
sheet.

A better job can be had by using a WBP plywood panel given several coats
of exterior varnish. I've had good results printing onto photographic
paper and then glueing the sheet to a prepared plywood panel. Once the
adhesive sets give the panel several coats of an exterior varnish,
preferably two-pack "Crystal" polyurethane. I've a sign made this way
that has lasted for five years without water damage or fading.