What British weather actually does to your paper

Rain is only half the problem. The real enemy of the outdoor sketcher in Britain is humidity — the slow, ambient damp of a drizzly afternoon, a sea fret rolling in off the coast, the condensation inside a rucksack left in a car boot. Paper is hygroscopic: it takes on moisture from the air around it. When that happens, watercolour paper cockles, pencil lines bloom and soften, and a book carried in a coat pocket for a month begins to smell faintly of cellar.

Add wind, which turns a light shower into something horizontal, and cold hands that fumble with wet closures, and you have conditions most sketchbooks were never designed for. The good news is that a handful of choices — paper weight, binding, cover material — make an enormous difference.

Paper weight and sizing: the first line of defence

The number on the cover is grams per square metre (gsm), and it tells you roughly how much abuse the paper will take.

• 90–110gsm: fine for pencil indoors, but it cockles, buckles and lets ink show through the moment damp gets in. Best avoided for field work.
• 140–200gsm: the practical middle ground. Handles pencil, pen and light washes, and shrugs off a bit of atmospheric moisture. Look for paper described as surface sized or internally sized — sizing slows the rate at which water soaks in and buys you a few extra seconds to work.
• 200–300gsm: necessary if you want to paint outdoors. Cold-pressed surfaces have a slight tooth that hides a little buckling; hot-pressed is lovely to draw on but shows every ripple.

If your budget stretches to 100% cotton paper, take it. Cotton rag survives rewetting, dries flatter and does not yellow the way wood-pulp papers can. Avoid heavily coated or very smooth papers outdoors — rain spots sit on the surface and dry as visible rings.

Binding, covers and closures

Where the water gets in matters as much as what it finds when it arrives.

• Casebound hardbacks with sewn signatures are the best all-round choice. The boards resist bending in a crowded bag, the sewn sections lie reasonably flat, and the spine holds together after a soaking.
• Wire and spiral bindings lie flat beautifully, but the metal rusts, the punched holes tear once damp, and the exposed page edges catch every drop.
• Coptic stitch gives you a flat-opening book with no metal at all — a genuinely good option for wet work.
• Glued or taped spines are the first thing to fail. Once adhesive takes on moisture it lets go, and you are left with loose signatures in a puddle.

Look for an elastic closure or wrap band. It keeps pages compressed, which helps the book dry flat and stops rain slipping between the sheets. A waxed cotton, oilcloth or coated board cover will not make a book waterproof, but it sheds drizzle long enough to get you home. Rounded cover corners last far better in a pocket than sharp ones, which fur up within a week.

Size, format and the two-book approach

Bigger is not better outdoors. Wind turns a large sheet into a sail, and a heavy book stays at home.

• A6 or A5 hardback fits a coat pocket or the lid of a rucksack, and you will actually carry it. This is the one that gets used.
• Landscape orientation suits horizons, sits better on a gatepost, and gives you a natural two-page spread for wide views.
• A5 or A4 for planned trips, where you know you will sit still for an hour with a rucksack to shelter behind.

Many outdoor sketchers keep two: a small, tough pocket book for snatched drawings in the rain, and a larger one for dry days and deliberate sessions. Thinner books have an advantage too — you finish them faster, so fewer pages are exposed to the worst of the weather.

Fieldcraft: keeping it dry in practice

A good sketchbook still needs a bit of help.

• Carry it in a dry bag or heavy-duty zip bag, and keep a plastic wallet for the page you are working on.
• A silica gel sachet in the bag costs nothing and mops up ambient moisture between trips.
• Take a sheet of blotting paper or kitchen roll to slip between damp pages.
• Pencil is the most forgiving medium in wet conditions. Water-soluble pen ink runs the moment a drop lands; a soft pencil (2B to 6B) cuts through the slight surface damp that makes harder grades scratch.
• For genuinely wet paper, a chinagraph or wax pencil will still mark.

If the book does get soaked, resist the radiator. Fan the pages open, stand it on its end somewhere airy and let it dry slowly, then press it under a couple of heavy books to flatten it. Heat cockles the paper and softens the adhesive in the spine.

Testing a book before the weather does

Before committing a new sketchbook to a winter, try three quick things. Put a single drop of water on an inside corner and watch how fast it spreads — if it sinks in instantly, the paper is unsized and will cockle badly. Flex the spine gently; a book that creaks and gaps at the hinge will not last a season. And check the closure, because a book that springs open in your bag is a book full of grit and rain.

Finally, accept that some damage is inevitable. A slightly wavy page and a soft grey edge where the rain caught it are part of the record. The drawings you make in poor weather are often the ones you remember, and a sketchbook that has clearly been outdoors is doing its job.