If one lives in Santa Fe with an ambient humidity of 5 going on 20 when
everybody feels hot and sweaty, it is clear that when you coat your paper
with solution the liquid is going to evaporate so quickly that it will not
sink very far into the paper. If you were to try that in London or Bath
where the average humidity is 60 and people start complaining when it
reaches 80, leaving the solution to dry naturally will take so long that it
will sink into the paper in an irregular manner leading to brush marks and
mottling. This effect is obviously also going to vary from one paper to
another as well. This is why I use a fan heater to dry my size and
solutions; in effect emulating Santa Fe conditions for platinum printing.
Moral : humidfiers, fan heaters and hygrometers should be sold by suppliers
to the platinum printing industry. Now I am off to the garden centre to get
some photographic chemicals.
Terry King