Dr Ph Martin's watercolour and ink products reviewed

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Dr Ph Martin's watercolour and ink products reviewed

Ian Sidaway tests the Dr Ph Martin's range of watercolour and ink products. Using Radiant Concentrated Watercolour, Hydrus Fine Art Watercolour and Bombay India Ink.

Ian Sidaway finds these watercolours and inks are quick and convenient to use, and add a punch to watercolour paintings.

'When I was at college in the late 1960s Dr Ph Martin’s Radiant Concentrated Watercolour was fugitive and, as such, I approached it with some degree of trepidation.

'These watercolours were, of course, intended for graphic and illustrative use; once photographed and processed for print, images were invariably consigned to the plan-chest draw, if not the rubbish bin, and were never intended for permanent display.

However, Salis International now market several high-quality and well respected ranges of permanent inks and liquid watercolour, including the Hydrus Fine Art Watercolour and Bombay India Ink.

The products

Radiant Concentrated Watercolour

Radiant Concentrated Water Colour

Dr Ph Martin’s Radiant Concentrated Watercolour is still available in 56 colours, including 12 fluorescents, but as previously stated, these are not recommended for work that is to be placed on display.

Formulated using aniline dyes rather than pigments they are not waterproof, neither are they permanent unless displayed under ultraviolet absorbing glass, Plexiglass or UVA acetate. However, it would be safe to use them for sketchbook work.

The watercolours are intended for use with brush, dip pen or airbrush on paper-based surfaces and come in 15ml and 60ml bottles with a dropper in the screw cap, and large 236ml bottles.

Also, I understand from the website that they can be made permanent on fabrics like silk and cotton if used with a mordant such as salt and vinegar, alum or calcium carbonate. It is received wisdom that artists have also successfully mixed the watercolour with acrylic paint to make colours that are both waterproof and lightfast.

As with all art materials, personal experimentation is the key here, and part of the fun!

Hydrus Fine Art Watercolour

Hydrus Fine Art Watercolour

Hydrus Fine Art Watercolour is available in 36 intermixable colours and is formulated using lightfast fine artist quality pigments.

This range is also sold in 15ml and 30ml bottles with a dropper in the screw cap, and large 236ml bottles.

They are AP approved non-toxic and are considered to be 25 to 50 per cent brighter than traditional watercolour.

They can be used with brush, airbrush and dip pen, including technical pens and fountain pens, although the latter may need some cleaning after use because of the pigment granules.

They are all completely transparent and archival.

Bombay India Ink

Bombay India Ink

Bombay India Ink is available in 24 colours; it is also made from fine artists’ pigments and is archival.

The inks are opaque and transparent, depending on colour, and are waterproof once dry.

They are AP approved non-toxic and can be used with brush, dip pen and, according to the manufacturer, technical pen.

The 15ml bottles don’t come with a dropper but the 30ml bottles do; there are also large 236 and 946 ml bottles – but it is unlikely you would ever need this kind of quantity.

Those using any of these products for the first time will find the starter sets provide a useful and comprehensive range of colours with which to work.

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For use on location work

The smallest size Hydrus Watercolours and Bombay Inks come in plastic bottles, making them an ideal choice when working on location.

Whilst the smallest watercolour bottle incorporates a dropper; the ink bottle does not, but the dropper can be purchased separately. The dropper is useful for putting quantities of ink on to a palette for mixing with water.

Be aware that it is possible to allow the watercolour to dry on a plastic or ceramic palette then make it useable again by rewetting. It is not possible to do this with the inks, so never allow them to dry on the palette.

The Radiant Concentrated Watercolours behave in a similar way to the Hydrus range but, being manufactured from dyes, can stain a plastic or enamel palette.

Avenue at Schönbrunn Vienna

Avenue at Schönbrunn Vienna, Bombay India Inks in Moleskine watercolour Sketchbook, (21x30cm)

The neat colours of the Bombay inks are less strident than those in the Hydrus watercolour range, which makes it easier to create more naturalistic colour mixes.

Brush and dip pen were used to create the image, above.

Remember that unlike the watercolours the inks are waterproof, so do not allow neat ink or colour mixes to dry on brushes or palettes.

Topiary at Schönbrunn Vienna

Topiary at Schönbrunn Vienna, Hydrus Fine Art Watercolour in Moleskine watercolour sketchbook, (21x30cm)

It is easy to use the Hydrus Watercolours to create bright decorative images but less easy to create paintings that are more naturalistic, as careful colour mixing is required. However, with care it is possible.

Brush and dip pen were used to apply the washes for the painting above. The inks are easy to clean from brushes and palettes

Granulation and other qualities

These watercolours, less so the inks, are extremely strong, concentrated and very bright; only a very small amount is needed to alter a mix radically, so take care to add only minute quantities at a time.

When dry, mixed washes of Hydrus Watercolour have a slight granular effect that is not unpleasant and can be put to good use and with practice all of the traditional watercolour effects and techniques can be used.

There is no noticeable granulation when the inks are mixed and diluted with water; they dry to leave a slight but pleasant surface sheen, as often seen when working with shellac based inks.

Washes of the Radiant Watercolours dry without any granulation.

Because they are so strong and bright, the liquid watercolours are ideal to use when learning about and practising colour mixing.

The white Hydrus Watercolour is opaque and turns the paint into a type of gouache or body colour when added to wash mixes.

The pigment content in the Hydrus and Bombay ranges tends to settle in the bottle, so always shake them well in order to distribute the pigment before using.

In essence all three products are to be used as you would any other ink or watercolour. They all show slightly different handling characteristics but nothing out of the ordinary.

The Radiant and Hydrus ranges behave in almost identical ways. They are quick to use, convenient and clean, with the added bonus that the non-fugitive colours can also be introduced into works that have been made with traditional pan or tube watercolour, to give that added punch.

Dr Ph Martin’s Radiant Concentrated Watercolour, Hydrus Watercolour and Bombay India Inks are distributed by Global Art Supplies
For more information and for stockists, telephone 01980 625 625 or visit the website,


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