When it’s too cold for papermaking, there’s always the option for dunking your hands in a warm gelatin solution…
Gelatin size produces the perfect surface for watercolour paper, it also gives the paper a lovely rattle
I soak the sheets in the size (3.5% rabbit skin glue gelatin solution with a pinch of alum added) and then meter the size off through a nip roller. The metering rollers are just a crude mangle and the sizing tub itself sits in a kind of ‘bain marie’ to keep the size solution warm. The bain marie is just a kids’s paddling pool filled with warm water which is circulated through a tea urn - this keeps the contents of the size tub at around 40 degrees C. All very ‘Heath Robinson’ but it works!
the sheets are then hung for the gelatin to set a little ( I wait until the sheen disappears)
Then I dry the sheets through a cylinder dryer. This is a photographic, electrically heated drum dryer. I’ve found that I can’t dry the sheets directly against the drum as this quickly becomes covered in gelatin, so I put a sheet of pellon in between the paper and the drum.
Finally, the paper goes into the dry press to fully flatten it down again.