The Al Secco Method of Mural Painting

By Conrad Schmitt
Published in "Church Property Administration" magazine, 1937

The fifteenth century, which witnessed the culmination of the fresco painting, is noted also for the work of the Van Eyck brothers, who popularized a new technique, that of painting in oils, which was soon to challenge the dominating position of the innovation.  Vasari tells us that al-fresco was “the only painting that Michelangelo thought worthy of man,” contrasting it with “oil painting” which, according to him, “was an art fit only for women and idle, incapable men.”

Nevertheless, the progress of oil was rapid and irresistible.  It permitted a wider range and greater brilliancy of colors, and also a greater facility of technique.  Gradually fresco fell into disuse and it seemed as though the older art would vanish completely under the growing sway of oil.  Today, the term “fresco” is commonly misunderstood and wrongly applied to all forms of mural painting, including oils.

There are modern artists of note who realize that the monopoly of oil has overreached itself and that for mural painting it would be advisable to return to the technique of the old masters.  This movement is strong in England, France, Germany and America.  American artists are turning to something different than oil for mural paintings.  There is E.W. Dubuque, whose genuine frescoes adorn Christ Church at Cranbrook, Mich., and the high school at Pawtucket, Mich.  There is Ray Boynton, who has done the panels of Mills college in the same technique.  To Boynton, the very difficulties of the exacting craftsmanship of genuine fresco painting are an advantage.

“In fresco”, he remarks, “the definite range of color and austerities of design and the limit of time in which the area must be completely finished are the real limitations.  They impose economies and austerities of design that are the essence of style.  This is the discipline of the wall which we have lost, the thing that must be experienced again if we are to recover the true language of decoration on the wall.”

Another modern artist, who advocates a return to the old craft, while disclaiming any malice toward oil, is La Montaigne St. Hubert, who says:  “Far be it from me to criticize the métier or craft of oil painting.  What I seek is rather to obtain for the fresco the place it has always occupied during the great art periods.  In France, the consciousness of this superiority has made enormous strides during the past few years and every day sees this opinion growing.”

He refers to the paintings of the primitives and contrasts them with work done in oil.  In his words, “no oil painting has been able to conserve, after a long existence, the exact colors which the artist created for it.  They all seem to fear the amber veil of things of the past.”

Here in America, it is not generally realized that pictures were not done entirely in oils until Van Eyck’s time, and then only on canvas, consisting largely of portraits and landscapes framed.  And ever since the introduction of this technique, oil paintings have caused the greatest concern in galleries.  Yellowing and cracking have been avoided only by heroic measures, while contemporaneous paintings in fresco and its allied technique, al secco, remain today as good as when executed, disintegrating only with the plaster itself.

Experiment of Leonardo

For a striking example of the inferiority of oil as a medium for mural work we are indebted to Leonardo and his inveterate zeal for experimentation.  He wished to augment the technique of fresco by the use of oil for retouching and so he has left us what is certainly the saddest instance of the destructive effects of age on oil in mural work.  The disintegration of Leonardo’s “Last Supper” has been pronounced by Signor Morelli, the Italian connoisseur, to be directly due to the use of oil pigment for greater effect in detail.  This painting, which was completed in 1499, was described by Vasari in 1666 as a blind picture.  As if to emphasize the guilt of oil as the destructive culprit, there exists on the wall opposite this painting another picture of very inferior execution, the “Crucifixion” of Montorfano, done in 1495.  It is in a state of good preservation, due, it must be inferred, to the conservative technique of pure fresco.

As a further example of the damaging effect of oil, mention should be made of the “Black Madonnas” of the Byzantine Primitives.  The hands and faces have turned very dark, certainly not the intention of these artists who used oil for its greater brilliance.  These bright complexions are ruined today as if in atonement for a youthful overindulgence in oil cosmetics.

Thus, we can readily understand why modern artists are growing restive under the dominance of the fad for oil and are turning back to the tradition of the great Cinquecento, especially for mural paintings.  But, is pure fresco, that is, the art of painting on fresh mortar with pure earth colors, especially adapted to our American climatic conditions?

The greatest obstacle is presented by our humid climate and by the gas and smoke-laden atmosphere of our modern cities.  We know that under similar conditions in France, England and Northern Germany attempts have been made to introduce the pure fresco but with poor success.

Crane, in his article “Of Mural Painting,”2 mentions the damp climate of France and England as unsuited to buono fresco.  He notes the exception of the Queen’s robing rooms in the House of Lords, with their decorations in pure fresco that must be carefully shielded against temperature and atmospheric changes.

Precursor of Buono Fresco
But there is a process approximating fresco that is unattended by these disadvantages.  It is an art which was practiced in Italy before and during the thirteenth century as the precursor of buono fresco.  It is al secco.  According to Vasari and Cennini, the secco and fresco techniques were mixed in water with casein as a binder.  In preparing for the work, the plaster is coated with pure lime, water and casein.  When it has thoroughly dried, another coat is applied.  Then casein, pure earth colors and lime, are mixed, keeping the wall moist during the application of the color.  In the drying process, oxygen causes a film to form on the surface, which is the secret of its enduring qualities.  This method of fresco-secco, as adapted and used chiefly by the Germans today, is durable, resistant to industrial gases and atmospheric changes and will bear washing.

Among the oldest examples of al secco paintings are the Pompeiian Murals, classed as secco paintings by James Ward in his work on Fresco Paintings, London, 1909.  Noteworthy modern examples of valuable and enduring work in al secco are found in the Royal Palace in Munich, done by von Klenze, the ceiling of the Bargerini Palace in Rome and the Romanesque church of St. Boniface in Munich.  Although the paintings in the latter are 95 years old, they are as fresh and beautiful as though only recently executed.

In America, too, may be found interesting examples of the use of al secco in mural decoration.  In his rare and interesting work on Early American Wall Paintings, E.B. Allen tells of a flourishing period in American colonial times when wealthy merchants and dignitaries had their walls done in water color by European artists.  Whether these works were in genuine fresco or in al secco is hard to determine in every case, but the probability is that most, if not all, were in the easier technique.

Survived the Centuries
These paintings, some of them of considerable artistic merit, have survived the centuries in good preservation.  More recent examples of painting known to be done in the secco method are not difficult to find in America.  There are the murals in the Sacred Heart Chapel, Notre Dame university, done by Gregori 65 years ago.  The colors, especially the blues, are as fresh and radiant as though recently applied.  However, only the technique deserves unqualified praise, as the judgment of the artist who, with the well-known penchant of the Italians, paints renaissance figures into a Gothic chapel, must be questioned.  While engaged in the restoration of these frescoes in 1933, the writer found them in excellent condition, excepting only where the plaster itself had disintegrated.

No matter how thoroughly or how many coats of oil paint may be applied, even if the final coat be stippled to a dull finish, in time the surface becomes glossy in spots, a yellowish tone appears and dirt accumulates on the surface.  Al secco will likewise become soiled in time but the soiling process is not nearly so rapid.  Its porous nature permits “breathing”.  Consequently no moisture gathers on the surface when the building is crowded and when excess heat is turned on during cold weather.  An unmoistened surface offers no clinging place for dirt.

Years afterward, when cleaning finally becomes necessary, the dry method is followed.  If the plaster is uncracked or unstained, the decorations can always be restored to their original state.  Even soap and water may be used without the fear of damaging the painting.  Thus accidental leaks in the roof, which would mean permanent defacement for an oil painting, will dry on the al secco surface without much defacement.  It is this waterproof quality of the al secco that explains the resistance to the elements of the exquisite paintings on the outside walls of the stucco farmhouses in the Austrian Tyrol and Upper Bavaria.  Rain has no effect on them nor does exposure to the sunlight fade the color.

From the foregoing, it may readily be understood why decorators are growing more disposed to return to the al secco method of mural painting, especially for churches.  They can offer to congregations a guarantee that the work will not have to be repainted every 15 or 20 years, and they can point out a splendid artistic tradition, dating back to a period when the religious spirit ennobled all the details of artistic craftsmanship.  Intelligent parish administration will demand al secco mural treatment.

2Arts and Crafts Essays, 1883, p. 149-160.

Conrad Schmitt is best known for his part in the revival of the medieval mural treatment known as al secco.  His frescoes in St. Louis Cathedral and the paintings of the Resurrection and Ascension are considered the largest ecclesiastical paintings in this country.  Noteworthy also are the restoration of the Gregory frescoes at Notre Dame University and the al secco decorations in St. Jerome’s, Holyoke, Mass., and St. Boniface, San Francisco, Calif.

•    Mural depicting “Adoration of the Trinity” above High Altar, St. Louis Cathedral, St. Louis, Missouri

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