How to build a portable mixed-media kit for train or café sketching that survives spills and tight spaces

I’ve spent years refining a compact mixed-media kit that fits comfortably under a café table, in a train seat pocket, or on my lap without turning a brief sketching session into a logistical puzzle. The trick isn’t just squeezing supplies into a small bag — it’s designing a system that protects fragile materials from spills, keeps inks and wet media tidy, and gives you enough variety to respond quickly to a scene.

Why a purpose-built portable kit matters

Sketching away from the studio forces decisions: you can’t carry everything, and you often have seconds to capture a light, a face, or a composition. A well-organised kit reduces friction. When I’m travelling by train or perched in a tiny café corner, I want to pick up my sketchbook and work, not untangle brushes or mop up a puddle of ink. Building a kit with spill-proof thinking and spatial efficiency lets me focus on looking and mark-making.

Choosing the right bag

Start with containment. I favour a small roll-top messenger or a cube-shaped pouch that sits upright on a table so things don’t tumble out. Waterproof or water-resistant fabrics (like coated canvas or nylon) are indispensable — accidental rain or a knocked-over coffee won’t immediately soak through. My go-to is a medium-sized zip cube inside a crossbody bag: the cube keeps supplies contained and the crossbody bag keeps my hands free.

• Size: palm-sized compartments for easy access, but big enough to hold an A5 sketchbook.
• Structure: firm base or internal sleeve to keep things upright.
• Material: water-resistant exterior and wipeable interior.

Essential items I never travel without

My kit balances wet and dry media so I can choose the mood of the sketch. Here are the core items I pack:

• Small A5 hardcover sketchbook (gives a firm surface and protects pages)
• Water brush (with refillable barrel) and a collapsible water cup
• Half-pan watercolour set or a pocket gouache set (I use Winsor & Newton Cotman half-pans)
• Compact folding palette or silicone mixing mat
• 1–2 pigment liners (0.1–0.5 mm) and a fountain pen with waterproof ink (I like Platinum Carbon or Sailor’s waterproof inks)
• Graphite stick or mechanical pencil
• Small stick eraser and a kneaded eraser
• Multipurpose brush (size 6–8 synthetic round) and a small mop brush for washes
• Permanent marker for bold marks and a white gel pen for highlights
• Pack of tissues, paper towel, and a small plastic bag for wet rubbish
• Microfibre cloth to protect surfaces and wipe brushes

How I prevent spills and leaks

Spills are the enemy of a portable kit. I’ve learned the hard way: a tipped water cup can ruin a sketchbook and a phone. These are my strategies:

• Use screw-top bottles: Replace open water pots with a small screw-top Nalgene or a water brush. Water brushes are my favourite because they combine brush and water and eliminate separate containers.
• Seal paint pans: Take pans that close securely or place removable pans into a small airtight tin. I sometimes stick a small square of foam between pans to stop them rattling and opening.
• Zip-lock everything wet: Put brushes, water brushes and wet tools in a zip-lock bag. If something leaks, the bag contains it.
• Double-layer protection: Wrap sketchbooks in a plastic sleeve or use a hardcover to keep pages safe from splashes.

Layout for tight spaces: how I set up in a café or on a train

Space is usually my constraint, not time. I aim for a one-handed set-up so I can hold a coffee in the other hand. My routine:

• Slip the sketchbook onto my lap or open it on the table with the spine against the armrest or window — this gives a steady surface.
• Keep a small tray (I repurpose a paperback-sized rigid board) in my bag; it acts as a table if necessary and creates a flat surface on my lap.
• Place the zip cube to the left or right (dominant hand side) and open one compartment — everything is within thumb reach.
• Use a single water brush or small collapsible cup; if using a cup, keep it on the side closest to you and away from edges.

Compact palettes and colour strategies

Space means colour choices must be deliberate. I use a small half-pan set with a mixture of warm and cool primaries (a cool and warm of red, blue and yellow), plus a neutral like Payne’s Grey. That limited palette allows me to mix a broad range of hues without overloading the kit.

For gouache I prefer a tiny tin of pre-mixed colours for quick layers and a few primary tubes squeezed into a plastic palette. If I want more vibrancy, I bring a small tube of Quinacridone Rose or Cadmium Yellow Deep — one or two high-chroma colours make a huge difference.

Tools for texture and mixed-media play

Part of the joy of sketching out and about is experimenting. I carry lightweight extras that add texture without bulk:

• Washi tape sample strip (for quick collage)
• Small glue stick or double-sided tape dots
• Chalk pastel stick or a few torn pastel scraps wrapped in paper
• Ink cartridge or tiny bottle of black India ink in a leak-proof vial
• Single-edge razor blade or craft knife in a safety cap for scratching back layers

Quick workflows I use on the move

I have a few go-to sequences that help me finish something usable in 10–30 minutes:

• 30-minute study: Pencil sketch (5–8 minutes), ink lines (5 minutes), quick watercolour wash (10–12 minutes), add gouache highlights and white pen (remaining time).
• 10–15-minute gesture: Pigment liner and water-brush wash — focusing on light and shadow, not detail.
• Layered mixed-media: Start with a collage base (washi + paper scraps), draw into it with pencil and ink, then add translucent watercolour layers.

Refilling, maintenance and smart replacements

After a day out, I clean brushes immediately with a microfibre cloth and rinse water brushes thoroughly. I top up water brushes before the next trip and replace any open pans that show signs of cracking. Keep a small spare of consumables (one extra water brush, a backup pen) in your home studio so you're never caught without essentials.

I’ve found that the most reliable kit is one you’ve tested on at least three different trips. Tweak items as you go — ditch what you don’t use and add what you miss. Over time you’ll develop a portable system that survives coffee spills, narrow train tables and the unpredictable joy of sketching outside of the studio.