The most commonly used suppliers of icon materials in the UK are Cornelissen, Stuart Stevenson and FitzPatrick. All of these are based in London.
L. CORNELISSEN & SONS: https://www.cornelissen.com
Cornelissen’s is the best known but has very high delivery costs, so it is best to make up a good size order. It is an amazing shop, near the British Museum, which looks as if it stepped out of a Victorian postcard! They were established in 1881 and their description – artist’s colourman – says it all. They source their own pigments which are high quality with great depth of colour – but you may have to grind some of them. I found yellow ochre and lapis-lazuli quite hard work. They do a range of traditional pigments, for those who prefer them -but a word of warning: you really need to check that the paints in your palette are lasting and chemically compatible with each other. this applies to all pigments, but more to the less stable early pigments. Of course, earths, which are the backbone of your icon palette are rarely unstable. They also sell an interesting range of locally sourced pigment (London pigment) by Lucy Mayes.
You can get everything you need, from your pencils, paper and brushes, through your whiting (or marble dust if you prefer, all your gilding equipment, golds and varnishes. They sometimes have gesso panels, but it is cheaper to buy the gesso and do your own. If you are doing big work with lots of gold, they have discounts on ten books of gold leaf and can advise on how many books of leaf you will need to cover a surface (that is edge to edge so I would add a third on that unless you are very experienced).
STUART STEVENSON http://www.stuartstevenson.co.uk
Stuart Stevenson has a very modest exterior but can compete with Cornelissen in range and expertise. It is a bit of a walk, down Clerkenwell Road, but worth every step. Alternatively, they give excellent phone advice. They are a family run firm, and I have phoned many times to ask advice on anything from the best gesso to the best gold size for assiste gilding. Postage is according to order, so better for small amounts. For me, the real gem of the shop is that they stock Maimeri Artist’s pigments, which are very fine ground – so a dream to use on faces. Their Yellow Ochre light, with English Red and either a Terre Verte or Ivory Black+Yellow Ochre Light= Green make the most extraordinary range of face shades. They also stock Sennelier colours, another reliable brand. I note they stock Gamblin colours, but have never used them: nor have I used Old Holland. If you try out a new colour range, I recommend getting a few background/ garment colours first, to get the feel of them.
In other materials, they have a good range of gold, and it is worth comparing prices with Cornelissen. Both firms have colour charts you can buy. They also stock Liberon oilless ultrafine steel wool, which is invaluable for smoothing bole surfaces for gilding ( a steel wool with oil in it ruins the gilding surface before you have begun). there is an interesting micro mesh sandpaper I haven’t yet tried out. I buy my gilding knives from there – they are light to handle and well balanced.
A.P. FITZPATRICK https://shop.apfitzpatrick.co.uk
AP FitPatrick, in Cambridge Heath Road, are geared to mail order and they prefer you to make an appointment to visit. They stock Kremer pigments – another reliable brand. They have a very interesting range of brushes – some nice Isabey squirrel hair for washes, string bound bristle brushes for gesso (better than a metal ferrule, which cuts the bristles when you are bashing away to get bubbles out) and a very good range of your icon painting sables. I have just found a Vaishali sable, which may become my brush of choice for assiste gilding.
They stock gessoed and ungessoed icon boards in limewood, various sizes including circular boards, at a reasonable price. Unfortunately, these don’t include boards with kovcheg/kivotos – the recessed ‘sacred space.’ They only sell acrylic gesso, so you will need to get your egg tempera gesso materials elsewhere.