Begin by identifying your painting goals. For detailed illustrations, you may prefer gouache with strong opacity and good covering power, while for soft washes, semi-opaque formulations work well. A 40ml tube offers a substantial amount of paint for longer projects, so select colors you’ll use often first and build a practical palette from there. Consider whether you mainly work with layering, blending, or bold color blocks to guide color selection.

Gouache requires balancing opacity, re-wettability, and the binder’s behavior as you layer colors. Pigment load affects how vibrant or transparent a stroke appears, while the binder (often gum arabic) influences how well the paint re-softens when you re-wet it. Understanding how these factors interact helps you control edge definition, blending, and how colors dry when applying multiple layers.

Beginner hobbyists and students will gain confidence with 40ml tubes due to the generous quantity and approachable consistency. More experienced illustrators may appreciate the convenience of larger tubes for extensive projects or ongoing studies. Regardless of level, the volume helps you experiment with color mixing and layering without frequent tube replacements.

Keep tubes tightly closed after use to prevent drying, and store them upright in a cool, dry place away from direct sunlight. When not in use, keep your palette clean and covered to minimize drying on the surface. Proper storage helps maintain color integrity and prolongs the life of your gouache set.

Avoid letting colors dry out on the palette by replenishing moisture and keeping the surface slightly damp while working. Build layers gradually rather than applying thick coats all at once, which can cause cracking. Clean brushes regularly to maintain pigment behavior, and test new mixtures on scrap paper before committing to your final piece to prevent surprises.

Look for a set or range that covers essential primaries and a mix of warm and cool tones to maximize mixing potential. A broad color range lets you create a wide spectrum of hues without needing excessive color-mixing, and having a few neutral tones helps you balance light and shadow across your artwork.