Gaddo Gaddi was a painstaking worker in mosaic, executing some works on a small scale entirely in eggshells of varying tints.  In the Baroncelli chapel in Florence is a painting by Taddeo Gaddi, in which occur the portraits of his father, Gaddo Gaddi, and Andrea Tafi.

About this time the delightful mosaic at St. Clemente, in Rome, was executed.  With its central cross and graceful vine decorations, it stands out unique among the groups of saints and seraphs, of angels and hierarchies, of most of the Roman apsidal ornaments.  The mosaic in the basilica of St. John Lateran is by Jacopo Torriti.  In the design there are two inconspicuous figures, intentionally smaller than the others, of two monks on their knees, working, with measure and compass.  These represent Jacopo Torriti and his co-worker, Camerino.  One of them is inscribed (translated) “Jacopo Torriti, painter, did this work,” and the other, “Brother Jacopo Camerino, companion of the master worker, commends himself to the blessed John.”  The tools and implements used by mosaic artists are represented in the hands of these two monks.  Torriti was apparently a greater man in some respects than his contemporaries.  He based his art rather on Roman than Greek tradition, and his works exhibit less Byzantine formality than many mosaics of the period.  On the apse of Sta.  Maria Maggiore there appears a signature, “Jacopo Torriti made this work in mosaic.”  Gaddo Gaddi also added a composition below the vault, about 1308.

The well-known mosaic called the Navicella in the atrium of St. Peter’s, Rome, was originally made by Giotto.  It has been much restored and altered, but some of the original design undoubtedly remains.  Giotto went to Rome to undertake this work in 1298; but the present mosaic is largely the restoration of Bernini, who can hardly be considered as a sympathetic interpreter of the early Florentine style.  Vasari speaks of the Navicella as “a truly wonderful work, and deservedly eulogized by all enlightened judges.”  He marvels at the way in which Giotto has produced harmony and interchange of light and shade so cleverly:  “with mere pieces of glass” (Vasari is so naively overwhelmed with ignorance when he comes to deal with handicraft) especially on the large sail of the boat.

In Venice, the Mascoli chapel was ornamented by scenes from the life of the Virgin, in 1430.  The artist was Michele Zambono, who designed and superintended the work himself.  At Or San Michele in Florence, the painter Peselli, or Guliano Arrigo, decorated the tabernacle, in 1416.  Among other artists who entered the field of mosaic, were Baldovinetti and Domenico Ghirlandajo, the painter who originated the motto:  “The only painting for eternity is mosaic.”