Part 6 (1/2)
OF SGRAFFITO WORK
The Italian words Graffiato, Sgraffiato, or Sgraffito, mean ”Scratched,”
and scratched work is the oldest form of graphic expression and surface decoration used by man.
The term Sgraffito is, however, specially used to denote decoration scratched or incised upon plaster or potter's clay while still soft, and for beauty of effect depends either solely upon lines thus incised according to design, with the resulting contrast of surfaces, or partly upon such lines and contrast, and partly upon an under-coat of colour revealed by the incisions; while, again, the means at disposal may be increased by varying the colours of the under-coat in accordance with the design.
Of the potter's sgraffito I have no experience, but it is my present purpose briefly and practically to examine the method, special apt.i.tudes, and limitations of polychrome sgraffito as applied to the plasterer's craft.
First, then, as to method. Given the wall intended to be treated: granted the completion of the scheme of decoration, the cartoons having been executed in several colours and the outlines firmly p.r.i.c.ked, and further, all things being ready for beginning work. Hack off any existing plaster from the wall: when bare, rake and sweep out the joints thoroughly: when clean, give the wall as much water as it will drink: lay the coa.r.s.e coat, leaving the face rough in order to make a good key for the next coat: when sufficiently set, fix your cartoon in its destined position with slate nails: pounce through the p.r.i.c.ked outlines: remove the cartoon: replace the nails in the register holes: mark in with a brush in white oil paint the s.p.a.ces for the different colours as shown in the cartoon, and pounced in outline on the coa.r.s.e coat, placing the letters B, R, Y, etc., as the case may be, in order to show the plasterer where to lay the different colours--Black, Red, Yellow, etc.: give the wall as much water as it will drink: lay the colour coat in accordance with the lettered s.p.a.ces on the coa.r.s.e coat, taking care not to displace the register nails, and leaving plenty of key for the final surface coat.
In laying the colour coat, calculate how much of the colour surface it may be advisable to get on the wall, as the same duration of time should be maintained throughout the work between the laying of the colour coat and the following on with the final surface coat--for this reason, if the colour coat sets hard before the final coat is laid, it will not be possible to sc.r.a.pe up the colour to its full strength wherever it may be revealed by incision of the design. When sufficiently set, _i.e._ in about 24 hours, follow on with the final surface coat, only laying as much as can be cut and cleaned up in a day: when this is sufficiently steady, fix up the cartoon in its registered position: pounce through the p.r.i.c.ked outlines: remove the cartoon and cut the design in the surface coat before it sets: then, if your register is correct, you will cut through to different colours according to the design, and in the course of a few days the work should set as hard and h.o.m.ogeneous as stone, and as damp-proof as the nature of things permits.
The three coats above referred to may be gauged as follows:--
_Coa.r.s.e Coat._--2 or 3 of sharp clean sand to 1 of Portland, to be laid about 3/4 inch in thickness. This coat is to promote an even suction and to keep back damp.
_Colour Coat._--1 of colour to 1-1/2 of old Portland, to be laid about 1/8 inch in thickness. Specially prepared distemper colours should be used, and amongst such may be mentioned golden ochre, Turkey red, Indian red, manganese black, lime blue, and umber.
_Final Surface Coat._--Aberthaw lime and selenitic cement, both sifted through a fine sieve--the proportions of the gauge depend upon the heat of the lime: or, Parian cement sifted as above--air-slaked for 24 hours, and gauged with water coloured with ochre, so as to give a creamy tone when the plaster dries out: or, 3 of selenitic cement to 2 of silver sand, both sifted as above--this may be used for out-door work.
Individual taste and experience must decide as to the thickness of the final coat, but if laid between 1/8 and 1/12 inch, and the lines cut with slanting edges, a side light gives emphasis to the finished result, making the outlines tell alternately as they take the light or cast a shadow. Plasterers' small tools of various kinds and knife-blades fixed in tool handles will be found suited to the simple craft of cutting and clearing off the final surface coat; but as to this a craftsman finds his own tools by experience, and indeed by the same acquired perception must be interpreted all the foregoing directions, and specially that ambiguous word, dear to the writers of recipes,--_Sufficient_.
Thus far method. Now, as to special apt.i.tudes and limitations. Sgraffito work may claim a special apt.i.tude for design whose centre of aim is line. It has no beauty of material like gla.s.s, no mystery of surface like mosaic, no pre-eminence of subtly-woven tone and colour like tapestry; yet it gives freer play to line than any of these mentioned fields of design, and a cartoon for sgraffito can be executed in facsimile, undeviated by warp and woof, and unchecked by angular tesserae or lead lines. True, hardness of design may easily result from this apt.i.tude, indeed is to a certain extent inherent to the method under examination, but in overcoming this danger and in making the most of this apt.i.tude is the artist discovered.
Sgraffito from its very nature ”a.s.serts the wall”; that is, preserves the solid appearance of the building which it is intended to decorate.
The decoration is in the wall rather than on the wall. It seems to be organic. The inner surface of the actual wall changes colour in puzzling but orderly sequence, as the upper surface pa.s.ses into expressive lines and s.p.a.ces, delivers its simple message, and then relapses into silence; but whether incised with intricate design, or left in plain relieving s.p.a.ces, the wall receives no further treatment, the marks of float, trowel, and sc.r.a.per remain, and combine to make a natural surface.
It compels the work to be executed _in situ_. The studio must be exchanged for the scaffold, and the result should justify the inconvenience. However carefully the scheme of decoration may be designed, slight yet important modifications and readjustments will probably be found necessary in the transfer from cartoon to wall; and though the ascent of the scaffold may seem an indignity to those who prefer to suffer vicariously in the execution of their works, and though we of the nineteenth know, as Cennini of the fifteenth century knew, ”that painting pictures is the proper employment of a gentleman, and with velvet on his back he may paint what he pleases,” still the fact remains, that if decoration is to attain that inevitable fitness for its place which is the fulfilment of design, this ”proper employment of a gentleman” must be postponed, and velvet exchanged for blouse.
It compels a quick, sure manner of work; and this quickness of execution, due to the setting nature of the final coat, and to the consequent necessity of working against time, gives an appearance of strenuous ease to the firm incisions and s.p.a.ces by which the design is expressed, and a living energy of line to the whole. Again, the setting nature of the colour coat suggests, and naturally lends itself to, an occasional addition in the shape of mosaic to the means at disposal, and a little glitter here and there will be found to go a long way in giving points of emphasis and play to large surfaces.
It compels the artist to adopt a limited colour scheme--a limitation, and yet one which may almost be welcomed as an apt.i.tude, for of colours in decorative work multiplication may be said to be a vexation.
Finally, the limitations of sgraffito as a method of expression are the same as those of all incised or line work. By it you can express ideas and suggest life, but you cannot realise,--cannot imitate the natural objects on which your graphic language is founded. The means at disposal are too scanty. Item: white lines and s.p.a.ces relieved against and slightly raised on a coloured ground; coloured lines and s.p.a.ces slightly sunk on a white surface; intricacy relieved by simplicity of line, and again either relieved by plain s.p.a.ces of coloured ground or white surface. Indeed they are simple means. Yet line still remains the readiest manner of graphic expression; and if in the strength of limitation our past masters of the arts and crafts have had power to ”free, arouse, dilate” by their simple record of hand and soul, we also should be able to bring forth new achievement from old method, and to suggest the life and express the ideas which sway the latter years of our own century.
HEYWOOD SUMNER.
OF STUCCO AND GESSO
Few things are more disheartening to the pursuer of plastic art than finding that, when he has carried his own labour to a certain point, he has to entrust it to another in order to render it permanent and useful.
If he models in clay and wishes it burnt into terra cotta, the shrinkage and risk in firing, and the danger in transport to the kiln, are a nightmare to him. If he wishes it cast in plaster, the distortion by waste-moulding, or the cost of piece-moulding, are serious grievances to him, considering that after all he has but a friable result; and though this latter objection is minimised by Mrs. Laxton Clark's ingenious process of indurating plaster, yet I am persuaded that most modellers would prefer to complete their work in some permanent form with their own hands.
Having this desirable end in view, I wish to draw their attention to some disused processes which once largely prevailed, by which the artist is enabled to finish, and render durable and vendible, his work, without having to part with it or pay for another's aid.