Technique and condition
The pieces of cotton canvas were prepared with a white pigmented ground, possibly an acrylic, after they had been stretched over the strainer. However, the commercially prepared linen appears to have a slightly different preparation, consisting of an unpigmented animal glue size layer beneath an oil-based primer.
The paint is oil and was applied exclusively by brush. All four canvasses were first covered with a grey imprimatura layer. This layer on the painting on the lower right is a slightly darker grey than that used on the other three paintings. These grey layers are smooth and rather thin and the canvas weave texture evident through them. An initial composition was then established using a lean and matt black paint to mark out the borders of the stripes (these lines are still visible between many of the stripes). The coloured stripes were then built up with several paint layers, all of which appear to have been of a very rich and buttery consistency. Typically there are a minimum of two or three distinct layers in each coloured stripe, but in some regions there appear to be even more. Unlike the imprimatura, these paints were not brushed out at all, and may have been applied in a single brushstroke. The result is a heavily contoured surface that is characterised by very distinctive brushmarking along the direction of the form (certainly the canvas weave texture is completely obscured, due to the high total paint thickness in these areas). The colours used for these layers are predominantly opaque, apart from the deep green colour used in the vertical bands which is more transparent, and all exhibit a high gloss. Most of them were applied wet on dry, but some of the top layers were applied using a wet-in-wet technique, for example the dirty yellow colour of the left hand painting has picked up the black layer beneath it and the bright yellow vertical bands often display streaks of the underlying orange. The application of at least the top paint layers on the three canvasses to the right of the work was executed with them bolted together (as these layers extend onto the other paintings at their joins), but the left hand painting appears to have been completed separately.
None of the paintings have a varnish layer and the work is not framed. The piece is in an excellent condition with no signs of any deterioration in the paint films and the rigid strainers are still providing sound support.