What Do the Symbols and Series Numbers Mean on a Paint Tube?

Understanding what the symbols and series numbers mean on oil, acrylic & watercolour paint tubes.

When you pick up a tube of oil, acrylic, or watercolour paint, you’ll often notice a set of symbols and a series number printed somewhere on the label together with the brand name and common pigment name. 

This article aims to clarify the meaning behind the symbols and various series numbers found in oil, acrylic, and watercolour paints.

We will start by looking at the series numbers usually marked as Series 1, Series 2, Series 3, and so on; for beginners, this can feel confusing, but understanding these series numbers is essential to making the right choice for your painting practice and your budget.

What does “Series” mean on your paint tube?

The series number on a tube of paint indicates its price band, not its quality. All Professional ranges, whether Winsor & Newton, Daler-Rowney, Liquitex, Golden, or Rosa, maintain the same high standard of lightfastness, permanence, and handling across most of the colours. The difference in series lies in the cost of the pigments used to make the paint.

• Series 1 paints are made with more affordable pigments and are the least expensive.
  

• Higher series (Series 2–5 or beyond) use rarer, historically precious, or more expensive pigments (e.g., Cobalt, Cadmium, or genuine Ultramarine) and therefore cost more.

Why do some colours with the same name cost more?

Two paints may share the same name across brands but fall into different series. For example, Cadmium Red will almost always be more expensive than Cadmium Hue. The reason is that the genuine pigment Cadmium is rare and costly to produce, while “Hue” indicates a modern synthetic alternative that imitates the colour but at a lower cost.

So, even though the quality of the paint base is consistent within a professional brand, the pigment itself determines the price point.

What does it mean when there are no series numbers on a tube of paint?

When a tube of paint doesn’t have a series number, like Liquitex BASICS Acrylic - 118ml Tubes, it usually means that the manufacturer has chosen to price all colours the same, rather than grouping them into series based on pigment cost.

If there’s no series number, it can mean one of two things:

• Flat pricing structure – All colours are sold at one price point (like student or mid-range paints such as Liquitex BASICS Acrylic - 118ml Tubes, System3, or Daler-Rowney Graduate Acrylics).
  
• Simplified range – The manufacturer wants to make it easier for artists to buy by avoiding multiple price bands, even if some pigments cost more to produce.

Examples of brands of paint with technical specifications but without series numbers.

Daler-Rowney Graduate Acrylic Colour Selection Set - 24 x 22ml Tubes Daler-Rowney Graduate Acrylic is an affordable range of water-based colours, ideal for students and amateurs looking for reliability and performance. These fast-drying, medium-body acrylic paint colours are smooth, easy to use, mix well together and are perfect for covering large areas or for everyday use. No series number but offers lots of important information regarding, lightfastness, pigment colour index name, health and safety information, conforms to ASTM and whether the paint is opaque, semi-opaque, transparent or semi-transparent.

 

Seawhite Water-Mixable Oil Paints - Set of 10 x 45ml Seawhite Water-Mixable Oil Paints provide the same excellent results as traditional oil paints while eliminating the need for harmful solvents and associated odours. Product Details: Can be mixed and cleaned with water. Made with high-grade vegan pigments and oils. The highest degree of lightfastness varies between 2-star (good) and 3-star (maximum). No series number but offers lots of important information regarding, lightfastness, pigment colour index name, health and safety information, conforms to ASTM and whether the paint is opaque, semi-opaque, transparent or semi-transparent.

 

Liquitex BASICS Acrylic - 118ml Tubes Liquitex Basics gives you the perfect balance of quality and economy. Made for all artists, formulated with the exacting Liquitex standard. They are made with the same lightfast, fine art pigments that are used in professional range, but just a lighter load. Product Details: Liquitex Basics Acrylic paint tubes are available in 72 brilliant colours. Great performance at a more affordable cost. Thick and creamy with a satin finish. Retains peaks and brush strokes. Completely safe for educational use.

 

Daler-Rowney System3 Original Acrylic Studio Set - 10 x 37ml Tubes This set of 10 contains a great range of System3 Acrylic Paints, perfect for students and professional artists alike. Daler-Rowney System3 Acrylics are versatile water-based colours made from high quality pigments. System3 Acrylic colours are lightfast, permanent (ranking from 3 to 4 stars for most of the colours), opaque (10 opaque and 20 semi-opaque colours), flexible and quick drying, making them suitable for applications on paper, artboard, wooden panels, canvas, metal, brick etc.

 

Brands of paint tubes with series numbers, and technical specifications.

Winsor & Newton Galeria Acrylic Tubes - 60m Winsor & Newton Galeria Acrylic offers excellent brilliance, professional quality pigments, opacity and permanence with a smooth, satin finish. Galeria uses the same pigments as the professional range or a similar pigment, but in a lower concentration. This makes it easy to use with, or transition to artists' grade when a wider choice and higher pigment strength is needed.

 

Winsor & Newton Professional Acrylic Paints - Set of 12 Tubes Winsor & Newton Professional Acrylic is a professional quality range of acrylic colour with unparalleled brilliance and intensity. This set contains twelve 20ml tubes of assorted Professional Acrylics. Thanks to the highest pigmentation levels combined with a unique new resin, Professional Acrylic colours remain as brilliant and intense when dry as they do when wet. An extremely versatile acrylic for all techniques and applications. Intermixable with all Winsor & Newton Professional Acrylic Mediums.

Winsor & Newton’s professional range of Acrylic paints provide the colour name, series number, pigment colour index, lightfastness rating and permanence rating.

 

Golden Heavy Body Artist Acrylics Essentials - Set of 6 x 59ml This set of Golden Heavy Body Acrylics contains six foundational colours with versatile properties, ideal for seamlessly blending a comprehensive spectrum of hues, tints, and shades. Golden Heavy Body Acrylics, characterised by their thick consistency, maintain texture for expressive artwork. These vibrant colours facilitate precise colour mixing without the use of fillers, extenders, or dyes. Excellent information given for series no, pigment colour index, lightfastness, Transparency/Opacity, health and safety guidelines, and conformability.

 

Liquitex Professional Heavy Body Acrylic - Classic Set of 12 x 59ml Liquitex Professional Heavy Body Artist Acrylic Paint has a thick consistency for traditional art techniques using brushes or knives, as well as for experimental, mixed media, collage and printmaking applications. Impasto (extra thick) applications retain crisp brush stroke and knife marks. Good surface drag provides excellent handling and blending characteristics with increased open-working time. High pigment load produces rich, brilliant, permanent colour. Liquitex Heavy Body paints are intermixable with all other paints and mediums in the Liquitex range.

What do the symbols mean on paint tubes?

Different paint manufacturers use symbols to help artists identify key information:

Permanence / Lightfastness

While both terms are often confused, 'permanence' and 'lightfastness' are distinct. 'Lightfastness' specifically refers to a colour's ability to resist fading when exposed to UV light. 'Permanence,' however, is a broader classification that encompasses not only a pigment's resistance to light but also its stability in various atmospheric conditions and the long-term chemical integrity of both the binder and the pigment. Winsor & Newton, for example, defines permanence as evaluating "not only lightfastness but also the film & chemical stability of the paint."  Some brands may choose to emphasize both, or only one, of these aspects. 

Winsor & Newton symbols: Uses a system as follows to rate the permanence of their paint;

• AA      – Extremely Permanent

• A         – Permanent

• B         – Moderately Durable

• C         – Fugitive

For further information on some colours, the rating may include one or more of the following additions:

• (i)         ‘A’ rated in full strength may fade in thin washes

• (ii)        Cannot be relied upon to withstand damp

• (iii)       Bleached by acids, acidic atmospheres

• (iv)       Fluctuating colour; fades in light, recovers in dark

• (v)        Should not be prepared in pale tints with Flake White, as these will fade

• (vi)       ‘A’ rated with a coating of fixative

Winsor and Newton opaque/ transparent symbols

T/O – Transparency/ Opacity

• Transparent colours are marked ‘T’ 

•  Semi-transparent ‘ST’. 

• Opaque colours are marked ‘O’ 

• Semi-opaque ‘SO’. 

Transparency however, is relative and the ratings are provided as a guide only. In addition, any thin film of colour will appear more transparent than a thicker one.

Winsor & Newton Professional Watercolour Complete Travel Tin - Set 24 Half Pans

Windsor & Newton Lightfastness

Lightfastness is shown with an ASTM rating for the pigment. The ASTM abbreviation stands for the American Society for Testing and Materials. This organisation has set standards for the performance of art materials including a colour’s lightfastness. In this system ‘I’ is the highest lightfastness available and ‘V’ is the lowest, though both ratings I and II are considered permanent for artists’ use.

Lightfastness symbols

• ASTM I: Excellent lightfastness, rated for 100+ years under normal gallery conditions.

• ASTM II: Very good lightfastness, rated for 100+ years under normal gallery conditions.

• ASTM III: Fair lightfastness, rated for 15-50 years.

• ASTM IV: Lower lightfastness, for colours that are more fugitive.

• ASTM V: Non-lightfast, meaning the colour is not stable and will fade significantly over time.

Windsor & Newton Designer Gouache  - 14ml tubes 

Daler-Rowney Symbols:

Daler-Rowney uses a ‘star’ rating system to rate the permanence rating of their paint ****

• 3*** -  4*** Stars: Paints like those in the System 3 acrylic range are generally rated this way, indicating they are highly resistant to fading and have excellent lightfastness. 

• Higher Star Ratings: For artist-quality paints, higher ratings (including a full four-star **** rating for many colours) signify greater permanence, which is crucial for professional work intended to last for a long time. 

Liquitex Acrylic Paint Symbols for their Basics range

Golden paint symbols;

These icons are used on Golden product labels and documents.

What is the Pigment Colour Index or Pigment Codes?
For more information click here

The Colour Index Numbers (or Pigment Codes) printed on your paint tube are one of the most important bits of information for artists — they tell you exactly which pigment or pigments were used to create that colour.

These codes are standardised internationally by The Colour Index™ created in 1924, so no matter the brand or country, the pigment code always refers to the same chemical pigment. This helps you understand the true identity, quality, and mixing behaviour of your paint — something that colour names alone can’t guarantee.

What the Colour Index Code Means

Each pigment has a unique code made up of:

• Two letters indicating the type of pigment colour group (e.g. PR, PY, PB)
  

• A number identifying the specific pigment or chemical composition.
  
  

For example:

• PR = Pigment Red

• PY = Pigment Yellow

• PB = Pigment Blue

• PG = Pigment Green

• PW = Pigment White

• PBk = Pigment Black

Why Colour Index Codes Are Important.

1.Consistency Across Brands

 Colour names like “Cadmium Red” or “Permanent Rose” can vary greatly between brands. But if you check the pigment code, you’ll know if two paints are actually the same pigment.

• Example: Winsor & Newton Cadmium Red (PR108) and Daler-Rowney Cadmium Red (PR108) are the same pigment.

• But Alizarin Crimson (PR83) and Permanent Alizarin Crimson (PR177 or PV19) are completely different pigments, even though their names sound similar.

2. Transparency & Mixing Behaviour

Each pigment behaves differently — some are opaque, some transparent, some granulate or stain. Knowing the pigment helps you predict how it will mix with others or layer in glazes.

3. Lightfastness & Permanence

Some pigments (like PR83 – Alizarin Crimson) are fugitive and fade over time, while others (like PR101 – Synthetic Iron Oxide Red) are very permanent. The code helps you choose colours that will last.

4. Avoiding “Mud” in Colour Mixing

When mixing colours, using paints made from a single pigment (one colour index code) produces cleaner results. Multi-pigment paints can easily make dull, muddy mixes. 

Examples of Common Pigment Codes and Their Names

 

Some Common terms explained.

 Some common Painting Terms Explained

 

To conclude,

When buying paint:

• Check the Colour Index Code – not just the colour name.

• For cleaner colour mixes, opt for single-pigment paints. These are typically found in professional ranges and come with a higher price tag. However, for those still learning, all graduate ranges offer excellent usability and deliver great results.

• Research the pigment for transparency, opacity, staining, permanence, and lightfastness.

The colour index is like the DNA of your paint — it tells you exactly what’s inside and how it will behave on your palette and canvas.

Final Thoughts

Whether you’re painting with oils, acrylics, or watercolours, the series system is there to help you understand pigment value, not paint quality. Beginners can safely start with Series 1–2 paints, while professionals often build a palette with a mix of affordable and premium pigments to capture subtlety and brilliance.

When browsing our range at ARTdiscount, check the series number, symbols, and pigment codes on each tube – they’re your guide to unlocking both creative freedom and value for money.