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

When you pick up a tube of oil, acrylic, or watercolour paint, you'll often notice a set of symbols and numbers printed somewhere on the label, usually below or alongside the brand and pigment name. If you've ever wondered what these symbols mean, this article is for you. We'll clarify the meaning behind these series numbers and symbols, and investigate how they can affect the final outcome of your artwork.

We'll start by taking a look at series numbers. They can be quite confusing for beginners, but understanding them is essential for making the right choice for you painting practice and budget.

What Does “Series” Mean on Your Paint Tube?

A big misconception around series numbers is that they indicate the quality of the paint, which is not always true. Rather, the series number indicate the price band based on the rarity of the pigment used in the paint's formulation. All professional-quality ranges – including Winsor & Newton, Daler-Rowney, Liquitex, Golden, and others – 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 commonly available, more affordable pigments, which means they cost less to produce and less for the consumer. Higher series, such as Series 2–5 or beyond, use rarer, historically precious, or more expensive pigments (like cobalt, cadmium, or genuine ultramarine) and therefore cost more to produce.

What Does It Mean If My Colour Says "Hue"?

Two paints may share a similar name across series bands but fall into different series. For example, you may find Cadmium Red in Series 4 of a paint, but you'll also find Cadmium Red Hue in Series 1. This is because the genuine pigment Cadmium is rare and costly to produce, while the Hue variant indicates that it is a modern synthetic alternative with similar colour handling as the genuine pigment, but with 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, 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, Daler-Rowney 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.

What Do the Symbols Mean On Paint Tubes?

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

Permanence / Lightfastness Rating

While both terms are often confused, 'lightfastness' and 'permanence' have distinct definitions. '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 emphasise one or both of these aspects. 

Each brand uses similar, but often distinct symbols and ratings to categorise their paints. In the following section, we'll explore a range of different manufacturer's ratings.

What is the Pigment Colour Index?

The Colour Index Numbers (or Pigment Codes) printed on your paint tube are one of the most important bits of information for artists. They're designed tell you exactly which 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 quality and mixing behaviour of your paint, which is 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 meaning Pigment Red, PY meaning Pigment Yellow, and PB meaning Pigment Blue) and number identifying the specific pigment or chemical composition.

Colour index codes are important because they allow for consistent colour mixing 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 made of the pigments.

For example, Winsor & Newton Galeria Cadmium Red Hue uses pigment PR112, and Daler-Rowney System3 Cadmium Red Hue uses PR112 – the exact same pigment. However, Winsor & Newton Galeria Hooker's Green uses the pigments PB15 and PY83, while Daler-Rowney System3 Hooker's Green uses the pigments PG7, PR101 Trans, and PY74. Same name, different pigments.

They also enable artists to predict transparency and colour mixing behaviour. Each pigment behaves differently; some are opaque, some transparent, some granulate or stain. Knowing the pigment before painting helps you predict how it will mix with others or layer in glazes. However, we recommend you experiment with paints on a separate page before committing anything to the final canvas.

Pigment codes are also a good way to predict lightfastness and permanence. Some pigments (like PR83, Alizarin Crimson) are fugitive and fade over time, while others (like PR101, Synthetic Iron Oxide Red) are extremely permanent. The code helps you choose colours that will last.

Reading pigment codes also helps you to avoid muddy colours when mixing. Using paints made from a single pigment (one colour index code) produces cleaner, more vibrant results. Multi-pigment paints, if not mixed carefully, can easily make dull, muddy mixes. 

Examples of Common Pigment Codes and Their Names

 

Winsor & Newton's Symbols

Winsor & Newton Permanence Ratings

Winsor & Newton uses a letter-based system to indicate their paints' permanence ratings.

• 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 Opacity Symbols

T/O – Transparency/ Opacity

• Transparent colours are marked ‘T’.

• Semi-transparent colours are marked ‘ST’. 

• Opaque colours are marked ‘O’.

• Semi-opaque colours are marked ‘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

Winsor & Newton's Lightfastness Ratings

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.

Winsor & Newton Designer Gouache  - 14ml tubes 

Daler-Rowney Symbols:

Daler-Rowney uses a star-based rating system to rank the permanence rating of their paint:

• Paints in the System3 Acrylic range are generally rated in the three to four star range, indicating they are highly resistant to fading and have excellent lightfastness.

• 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

Liquitex have put together their own symbol explanation image, which you can see below.

GOLDEN Heavy Body Acrylic Paint Symbols

Likewise, GOLDEN have put together a symbol explanation image, which you can see below.

 Some Common Painting Terms Explained:

When purchasing paint, checking the colour code is an extremely useful step to working out whether or not it's right for you. Luckily, at ARTdiscount, many of the paints we sell have their pigment codes listed right here on the website! Simply click onto the swatch and read the information for yourself.

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.

Brands of Paint Tubes with Series Numbers and Technical Specifications

Winsor & Newton Galeria Acrylics 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 Winsor & Newton Professional Acrylic is a professional quality range of acrylic colour with unparalleled brilliance and intensity.  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 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 Artist Acrylics 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.

Examples of Brands of Paint with Technical Specifications but Without Series Numbers

Daler-Rowney Graduate Oils and Acrylics Daler-Rowney Graduate Oils and Acrylics are an affordable range of colours, ideal for students and amateurs looking for reliability and performance. Graduate Oil colours are smooth, easy to use, and mix well together, drying to a low gloss satin sheen within 5 days. 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 Acrylics 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.

Swatch This Space

When browsing on the ARTdiscount store, you can find pigment, opacity, and lightfastness information by simply clicking on a colour swatch. Most colours will feature the most important information that you need to know to make an informed choice.

Remember, no matter whether you're painting with oils, acrylics, or watercolours, the series system exists to help you understand pigment value, not the quality of paint. Beginner, hobbyist, and student artists can build up an excellent palette of colours using only series 1 or 2 paints, while professionals and more experienced artists may wish to add more premium pigments to build a more subtle and brilliant palette.