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.



These old processes are modelling in Stucco-duro and Gesso.



Stucco-duro, although of very ancient practice, is now practically a

lost art. The materials required are simply well-burnt and slacked lime,

a little fine sand, and some finely-ground unburnt lime-stone or white

marble dust. These are well tempered together with water and beaten up

with sticks until a good workable paste results. In fact, the

preparation of the materials is exactly the same as that described by

Vitruvius, who recommends that the fragments of marble be sifted into

three degrees of fineness, using the coarser for the rough bossage, the

medium for the general modelling, and the finest for the surface finish,

after which it can be polished with chalk and powdered lime if

necessary. Indeed, to so fine a surface can this material be brought,

and so highly can it be polished, that he mentions its use for mirrors.



The only caution that it is needful to give is to avoid working too

quickly; for, as Sir Henry Wooton, King James's ambassador at Venice,

who greatly advocated the use of stucco-duro, observed, the stucco

worker "makes his figures by addition and the carver by subtraction,"

and to avoid too great risk of the work cracking in drying, these

additions must be made slowly where the relief is great. If the relief

is very great, or if a figure of large dimensions is essayed, it may be

needful even to delay the drying of the stucco, and the addition of a

little stiff paste will insure this, so that the work may be

consecutively worked upon for many days.



From the remains of the stucco work of classic times left us, we can

realise how perfectly workable this material was; and if you examine the

plaster casts taken from some most delicate low-relief plaques in stucco

exhumed some ten years ago near the Villa Farnesina at Rome, or the

rougher and readier fragments of stucco-duro itself from some

Italo-Greek tombs, both of which are to be seen in the South Kensington

Museum, you will at once be convinced of the great applicability of the

process.



With the decadence of classic art some portion of the process seems to

have been lost, and the use of pounded travertine was substituted for

white marble; but, as the bassi-relievi of the early Renaissance were

mostly decorated with colour, this was not important. The ground colours

seem generally to have been laid on whilst the stucco was wet, as in

fresco, and the details heightened with tempera or encaustic colours,

sometimes with accessories enriched in gilt "gesso" (of which

hereafter). Many remains of these exist, and in the Nineteenth Winter

Exhibition of the Royal Academy there were no less than twelve very

interesting examples of it exhibited, and in the South Kensington Museum

are some few moderately good illustrations of it.



It was not, however, until the sixteenth century that the old means of

producing the highly-finished white stucchi were rediscovered, and this

revival of the art as an architectonic accessory is due to the

exhumation of the baths of Titus under Leo X. Raphael and Giovanni da

Udine were then so struck with the beauty of the stucco work thus

exposed to view that its re-use was at once determined upon, and the

Loggia of the Vatican was the first result of many experiments, though

the re-invented process seems to have been precisely that described by

Vitruvius. Naturally, the art of modelling in stucco at once became

popular: the patronage of it by the Pope, and the practice of it by the

artists who worked for him, gave it the highest sanction, and hardly a

building of any architectural importance was erected in Italy during the

sixteenth century that did not bear evidence of the artistic craft of

the stuccatori.



There has just (Autumn, 1889) arrived at the South Kensington Museum a

model of the central hall of the Villa Madama in Rome, thus decorated by

Giulio Romano and Giovanni da Udine, which exemplifies the adaptability

of the process; and in this model Cav. Mariani has employed stucco-duro

for its execution, showing to how high a pitch of finish this material

is capable of being carried. Indeed, it was used by goldsmiths for the

models for their craft, as being less liable to injury than wax, yet

capable of receiving equally delicate treatment; and Benvenuto Cellini

modelled the celebrated "button," with "that magnificent big diamond" in

the middle, for the cope of Pope Clement, with all its intricate detail,

in this material. How minute this work of some six inches diameter was

may be inferred from Cellini's own description of it. Above the diamond,

in the centre of the piece, was shown God the Father seated, in the act

of giving the benediction; below were three children, who, with their

arms upraised, were supporting the jewel. One of them, in the middle,

was in full relief, the other two in half-relief. "All round I set a

crowd of cherubs in divers attitudes. A mantle undulated to the wind

around the figure of the Father, from the folds of which cherubs peeped

out; and there were many other ornaments besides, which," adds he, and

for once we may believe him, "made a very beautiful effect." At the same

time, figures larger than life, indeed colossal figures, were executed

in it, and in our own country the Italian artists brought over by our

Henry VIII. worked in that style for his vanished palace of Nonsuch.

Gradually, stucco-duro fell into disuse, and coarse pargetry and

modelled plaster ceilings became in later years its sole and degenerate

descendants.



Gesso is really a painter's art rather than a sculptor's, and consists

in impasto painting with a mixture of plaster of Paris or whiting in

glue (the composition with which the ground of his pictures is laid)

after roughly modelling the higher forms with tow or some fibrous

material incorporated with the gesso; but it is questionable if gesso is

the best vehicle for any but the lowest relief. By it the most subtle

and delicate variation of surface can be obtained, and the finest lines

pencilled, analogous, in fact, to the fine pate sur pate work in

porcelain. Its chief use in early times was in the accessories of

painting, as the nimbi, attributes, and jewellery of the personage

represented, and it was almost entirely used as a ground-work for

gilding upon. Abundant illustration of this usage will be found in the

pictures by the early Italian masters in the National Gallery. The

retables of altars were largely decorated in this material, a notable

example being that still existing in Westminster Abbey.



Many of the gorgeous accessories to the panoply of war in mediaeval

times, such as decorative shields and the lighter military

accoutrements, were thus ornamented in low relief, and on the

high-cruppered and high-peaked saddles it was abundantly displayed. In

the sixteenth-century work of Germany it seems to have received an

admixture of finely-pounded lithographic stone, or hone stone, by which

it became of such hardness as to be taken for sculpture in these

materials. Its chief use, however, was for the decoration of the

caskets and ornamental objects which make up the refinement of domestic

life, and the base representative of it which figures on our

picture-frames claims a noble ancestry.



Its tenacity, when well prepared, is exceedingly great, and I have used

it on glass, on polished marble, on porcelain, and such like

non-absorbent surfaces, from which it can scarcely be separated without

destruction of its base. Indeed, for miniature art, gesso possesses

innumerable advantages not presented by any other medium, but it is

hardly available for larger works.



Time and space will not permit my entering more fully into these two

forms of plastic art; but seeing that we are annually receiving such

large accessions to the numbers of our modellers, and as, of course, it

is not possible for all these to achieve success in, or find a means of

living by, the art of sculpture in marble, I have sought to indicate a

home-art means by which, at very moderate cost, they can bring their

labours in useful form before the world, and at the same time learn and

live.



G. T. ROBINSON.