I think it is safe to say that you don't have to worry. Specific
Gravity is effectively related directly to density. Density in turn is
dependent on the volume and mass of a material. As mass does not change
with temperature, but volume does, we come down to the only critical
variable being the temperature dependence of the material's volume.
To get a 1% variation in density, you need to get roughly a 1% change
in volume (actually 0.9% or 1.1% depending on whether we're contracting
or expanding).
Specific gravity is the ratio of the density of an equal volume of
water at 4C (1 gram/cm^2) with that of the material, so that's a 1%
variation in specific gravity too.
From a pervious message on Beaume by Peter Marshall:
> 0 degrees equals a specific gravity of 1,
> 1 degree equals 1.007,
> 2 degrees equal 1.013,
> 3 degrees equal 1.02
> and so on (it says).
So a 1% variation is specific gravity translates to roughly 1.5 degrees
Beaume. Maybe that is a significant change for gum printing (I don't
know!).
However, a 1% change in volume is fairly significant, and probably
unlikely for gum over a 10F temperature change. If you have a measuring
cylinder accurate to 1ml test it yourself. A 1 litre cylinder would be
ideal. Fill it to 950ml and see how it's volume varies with temperature.
Anything less than a 30ml variation is less than 1 degree Beaume, and
anything less than 10ml is less than a third of a degree. My guess is
you'll get less than 2ml, which is less than a tenth of a degree. (I
doubt if manufacturing tolerances are much higher than that.)
Do the tests yourself and see what happens.
cheers
-steve