Ultimate Guide to Watercolor Paper

When it comes to watercolor painting, the watercolor paper you choose can make or break your artwork. It's not just a surface to paint on—it's an essential tool that affects how your pigments interact, how water flows, and how vibrant your final piece appears. Whether you are a professional artist or a beginner learning to master washes and blends, understanding watercolor paper is key to achieving consistent, beautiful results.

Unlike ordinary drawing or printing paper, watercolor paper is specially designed to handle large amounts of water without disintegrating or warping. It's made through specialized processes, often using cotton fibers, wood pulp, or a combination of both. Each material and manufacturing method produces different textures, absorbency levels, and strengths.

In this guide, we'll dive deep into its materials, textures, sizing, color options, and other critical characteristics. You'll also learn why paper buckles when wet, how to stretch it properly, and how to recognize which side to paint on.

Key Takeaways

• Watercolor paper is specifically made to handle water and pigments without tearing or pilling.

• It is commonly made from cotton, wood pulp, or mixed fibers—each providing different performance qualities.

• There are three main textures: hot-pressed (smooth), cold-pressed (medium texture), and rough (coarse texture).

• Sizing (internal and external treatment) controls absorbency and paint flow.

• Properly stretching watercolor paper prevents buckling and ensures a flat, professional finish.

• Understanding the deckle edge and paper color helps artists choose high-quality materials for professional presentation.

What is Watercolour Paper Made of?

The foundation of watercolor paper lies in its fibers. The composition of the fibers determines strength, absorbency, and texture—all of which influence your painting experience.

1. Cotton Fiber Paper

Cotton watercolor paper is considered the highest quality option. Made from 100% cotton linters or rags, it provides unmatched durability and absorbency. Cotton fibers are long and interwoven, allowing the paper to withstand multiple washes and reworking without pilling or tearing.

Advantages:

• Excellent absorbency and texture retention

• Even pigment distribution

• Long-lasting and archival quality

2. Wood Pulp Paper

Wood pulp watercolor paper (cellulose paper) is more affordable but less durable. It absorbs water faster and can sometimes buckle more easily. This type of paper is ideal for beginners, students, or practice sessions.

Advantages:

• Cost-effective and widely available

• Suitable for light washes and sketching

• Good for testing colors and techniques

3. Mixed Fiber Paper

Some papers blend cotton and wood pulp to balance quality and price. These hybrid papers provide improved strength compared to pure cellulose papers, yet they remain affordable.

Example: Canson XL Watercolor Paper uses a wood pulp base with enhanced sizing to mimic higher-grade performance.

Texture

The texture of watercolor paper greatly influences the visual outcome and painting technique. The surface is created by the mold or pressing process used during manufacturing.

1. Hot-Pressed (HP)

Hot-pressed watercolor paper is smooth and fine-grained. It's ideal for detailed linework, botanical illustrations, and realistic portraits. Paint sits on the surface longer, allowing for crisp edges and controlled blending.

Best for: Fine details, pen & ink, and minimal water usage

2. Cold-Pressed (CP) or NOT (Not Hot Pressed)

Cold-pressed watercolor paper has a slightly textured surface, offering a balance between detail and water control. It's the most popular texture among watercolor artists.

Best for: Versatile techniques, including washes, glazing, and wet-on-wet

3. Rough

Rough watercolor paper has a pronounced texture, created by natural felts during the drying process. The peaks and valleys create a dramatic, grainy effect—perfect for expressive landscapes and bold strokes.

Best for: Expressive painting, texture-rich effects, large washes

Colour

Watercolor paper typically comes in shades of white, natural white, or cream. The color affects how pigments appear once dry.

• Bright white paper enhances color vibrancy and contrast. It's favored for modern and vivid works.

• Natural white paper provides a softer tone and more traditional look, ideal for portraits or landscapes.

• Tinted watercolor papers (e.g., gray, tan) are becoming popular for mixed media or gouache work.

When choosing, remember that the base tone of your watercolor paper acts like a built-in background—it influences all transparent layers applied on top.

Sizing

Sizing is a crucial process that defines how watercolor paper interacts with water and pigment. Without sizing, the paper would absorb water too quickly, causing colors to dull and spread uncontrollably.

Types of Sizing

1. Internal Sizing:
   Added during the paper pulp stage, it affects absorbency from within. Most artists' papers use gelatin or synthetic substitutes.

2. External (Surface) Sizing:
   Applied after sheet formation, it enhances surface strength and controls water spread.

Why It Matters

• Prevents paint from soaking through

• Allows controlled blending and lifting

• Enhances durability during multiple washes

Why Does Paper Buckle When Wet?

Watercolor paper buckles because water causes fibers to expand unevenly. When one side absorbs more water, it swells and stretches, creating waves or ripples.

Factors Influencing Buckling

• Paper weight (thinner sheets buckle more)

• Uneven wetting or drying

• Excessive water or pooling

• Lack of stretching before use

How to Prevent Buckling

• Use 300 gsm (140 lb) or heavier paper

• Stretch the paper before painting (see next section)

• Secure edges with tape or clips

• Paint evenly across the surface

Paper weight plays a vital role. Below is a quick reference:

How to Stretch Watercolour Paper

Stretching helps eliminate buckling by pre-expanding and drying the paper before painting.

Step-by-Step Guide

1. Soak the Paper
   Immerse the sheet in clean water for 3–5 minutes (for 300 gsm paper) or up to 10 minutes (for heavier paper).

2. Prepare a Board
   Use a wooden drawing board or gator board.

3. Lay and Tape
   Remove the paper, gently shake off excess water, and lay it flat on the board.

4. Secure Edges
   Use gum tape (not masking tape) to fix all edges. Make sure the tape overlaps both paper and board.

5. Let it Dry
   Allow the paper to dry completely—at least 24 hours. It will tighten as it dries, resulting in a perfectly flat surface.

Once stretched, your watercolor paper can handle heavy washes without warping.

Is There a Correct Side to Work on Watercolour Paper?

Yes, watercolor paper has a correct side—often referred to as the front (felt side) and the back (wire side).

• The felt side (front) is usually smoother and designed for painting.

• The wire side (back) may be slightly rougher due to the mold's texture.

Manufacturers often watermark their paper to indicate the correct orientation. If the watermark is readable from the front, that's the side you should paint on.

However, many artists experiment with both sides to achieve different effects. The important part is consistency throughout your project.

What is a Deckle Edge?

A deckle edge is the naturally feathery, irregular edge found on hand-made or mold-made watercolor paper. It's formed when the pulp settles unevenly against the mold frame.

Why Artists Love Deckle Edges

• They signify authentic, high-quality paper.

• Provide an aesthetic, handmade look when artworks are displayed without trimming.

• Often used for fine art prints and professional portfolios.

Some machine-made papers mimic deckle edges for decorative appeal, but true deckle edges remain a hallmark of traditional craftsmanship.

Conclusion

Choosing the right watercolor paper is just as critical as selecting the right paints or brushes. The paper's composition, texture, color, and sizing all determine how pigments flow and interact with water. High-quality 100% cotton papers deliver superior durability and vibrant results, while affordable cellulose papers are perfect for practice and experimentation.

By understanding the different textures, weight classes, and surface treatments, you can tailor your materials to your artistic goals—whether that's achieving fine detail on smooth hot-pressed sheets or expressive granulation on rough textures.

Don't forget that stretching your paper and knowing which side to use can drastically improve your results. And for those who appreciate craftsmanship, the deckle edge remains a timeless sign of quality.

In essence, the right watercolor paper transforms the painting process from struggle to synergy—allowing your creativity to flow as freely as your colors.

FAQs

Q1: How can I tell if my paper is 100% cotton?
A: Check the packaging—premium brands clearly state "100% cotton." Cotton paper also feels softer and more pliable than cellulose paper.

Q2: Does heavier paper always mean better?
A: Not necessarily, but heavier paper (640 gsm or more) resists buckling better and may not require stretching.

Q3: Can I use watercolor paper for gouache or ink?
A: Yes, watercolor paper works wonderfully with gouache, ink, and other wet media due to its absorbent nature.

Q4: How should I store watercolor paper?
A: Store it flat in a dry, cool environment, away from direct sunlight or humidity. Use folders or plastic sleeves to prevent damage.

Q5: Why do my colors look dull on cheap paper?
A: Low-quality paper absorbs pigments too quickly, causing them to lose brightness. Opt for sized, acid-free watercolor paper for better color retention.

Q6: What's the difference between mold-made and machine-made paper?
A: Mold-made watercolor paper is more durable and has a natural texture, while machine-made paper tends to be smoother and less absorbent.

Q7: Can I re-use watercolor paper?
A: If the surface hasn't degraded, you can lightly scrub and repaint over certain areas, but overworked papers may lose sizing and texture.