A previous post has already introduced the subject of a most useful work that was published in the 1930s – Parsons’ Decorative Finishes. Subsequently I have used it as a ‘prompt’ for posts dealing with Water Paint, Flat Finishes; Gloss Enamel Finishes and several other types of paint.
The book is divided into 17 sections and one of these (Section Twelve) will be considered in this post which looks at the Plastic Paint offered by Thomas Parsons’ at the time.
Plastic or Texture Paints
‘WATER-TEX’ was supplied in powder form, which when mixed with water was applied as a paste to the wall. This could then be manipulated with a number of tools to give an almost unlimited variety of textured surfaces. The surface could then be treated with ‘Parso-Glaze’ to provide a decorative finish. It was considered particularly suitable for Cinemas, Restaurants etc.
Specification for securing first-rate results
NEW AND OLD WORK
Upon Wood or Plaster -
Assuming that the plaster is thoroughly dry, apply:
a) One coat of ‘Water-Tex’.
b) One coat of Parsons’ Body White Undercoating Paint.
c) One coat of Parsons’ Undercoating ‘Parso-Glaze’.
d) One coat of Parsons’ ‘Parso-Glaze’, and wipe off the high lights with rag or rubber squeegee.
e) One coat of Parsons’ Extra Pale Egg-shell, Extra Pale Dead Flat or Pale Copal Varnish.
Requirements of Plastic Paints
The formulation of a plastic paint is a good example of the seemingly impossible range of requirements that the paint chemist must cope with and called for a careful consideration of the various functions that it would serve. Plastic paint -
a) Must adhere well to both smooth and rough surfaces.
b) Must possess sufficient elasticity to accommodate any expansion or contraction of the ground without cracking.
c) Must expand and contract uniformly in itself and must not become brittle.
d) Must be capable of ready manipulation even when applied in a thick coat and shaping made by the craftsman’s tools.
e) Must not sag or dissolve away into the surface.
f) In spite of heavy coats it must maintain its toughness.
g) Must be capable of receiving paint as a decorative finish and should not exert any chemical action on such finishes.
h) Must set and dry out within a reasonable time.
i) Finally, it must not be too expensive.
Formulation of Plastic Paints
There were a number of compositions on the market and manufacturers dealt with the above requirements in different ways, but a typical composition might have been something like this:
a) China clay or gypsum would provide the body of the material.
b) Gum Arabic to promote adhesion.
c) Casein to give stability during manipulation and to assist in binding the material together and give elasticity.
d) Powdered mica to act as a bonding material (having a similar action to that of hair in lime and hair plaster).
e) Plaster in sufficient proportion to give set and to promote hardness.
Bottom) The relief is produced with a dabbing motion of the sponge, the imitation joints being incised with a chisel, etc. before completely dry.1
It was essential that the mixing of plastic paint was carried out thoroughly in order to eliminate all lumps. Because of the thickness of the coating substantial amounts were required for the treatment of a small room – the coverage rate was given as approximately one pound of powder for each square yard.
Stirring was usually carried out with a stick, but a more effective tool could be made by screwing the lid of a small paint tin to the end of a short length of broom handle to make a plunger.
A clean bucket would be filled to about one-third full with warm water and enough powder added to bring the contents just above the half-way mark. The amount of powder would depend on the kind of texture required – if a light stipple was indicated the mixture would be considerably thinner than when a fairly high relief was wanted. The mixture was then stirred with the plunger with a vigorous semi-circular movement until a fairly thick cream was obtained.
Sufficient paint had to be mixed to cover the entire surface for, if it was necessary to make up a fresh batch and this differed from the first, it would affect the appearance of the work.
Bottom) A rubber stippler and palette knife were used to get the effect shown here.
Techniques of Application
The following contemporary account gives an indication of the range of tools and techniques that might be employed to produce decorative effects:
“The impromptu tools that may be brought into play for manipulating plastic compo are innumerable – rubber combs and stipplers, flat blocks for pressing to the surface and pulling up patterns by suction, ring brushes for producing rosettes, made by cutting out the centre bristles from large sash tools. Thin metal stamping waste to act as stencils through which plastic compo may be pressed, leaving a pattern when the ‘stencil plate’ is withdrawn; rollers of various patterns, large curtain rings of wood or quoit rings, crumpled paper or rag, sponges, wooden sticks for literally drawing patterns as in Sgraffito work, or for making ashlar ‘joints’ or tile ‘joints’, various kinds of knives to produce a great variety of patterns, paper leaves which may be laid on the brushed out or stippled surface and withdrawn to leave a textured impression of their shapes, air ballons dabbed to the surface, celluloid squares or pieces of rubber floor cloth to smooth the surface.2
Another source pointed out the importance of scale. What might be appropriate for the auditorium of a cinema would be totally out of place in a small room.
Bottom) Produced with a wood or rubber roller.
Other Forms of Plastic Paint
Plastic paint was also produced in a ready-mixed form, with an oil binder, although this tended to be employed on much smaller scale projects than the powder variety. This was supplied in large containers and was of such a consistency that a stout stick was required to stir it before use. Some manufacturers supplied special thinners and these were added if a lighter body was necessary.
Simpler forms could be mixed by a competent painter using water paint mixed with fine dental plaster. There are even accounts of adding such things as marshmallow root, ground rice and treacle.
Some of the effects achievable with plastic paint were quite sophisticated, as can be seen in this example:
Decline in Use
Although still visible in the early 1970s, by that stage plastic (or textured) paint was usually employed in the form of Artex and then only on ceilings.
The main drawback with plastic paint was that once one became tired of the finish its removal was difficult.
The powdered form was susceptible to steam-stripping or by soaking with water and scraping. However, if a paint or glaze had been applied the film would need to be broken in order to allow water or water vapour to penetrate.
The oil-bound version could be stripped by using a blowlamp or a solvent paint remover, but several applications would often be necessary. Careful rubbing down with sandpaper would gradually restore a more even surface to the walls.
The rubbing down of plastic paint inevitably created dust, which could be hazardous, especially in the case of Artex applied before the mid-1980s, as white asbestos was used to strengthen it.
1 The technique of scribing joint lines is explained in my post on Imitation Stone paints.
2 James Lawrance. Painting from A to Z. The Sutherland Publishing Co. Ltd. 1938. p.316.
I am afraid that Papers and Paints do not sell textured paints.