The treatise of Armenini (1587) was published at Ravenna, and he himself was of Faenza, so that his authority, again, cannot be considered decisive as to the Venetian practice. After all, he recommends the addition of "common varnish" only for the ground or preparation, as a consolidating medium, for the glazing colours, and for those dark pigments which are slow in drying. Many of his directions are copied from the writers last named; the recipes for varnishes, in particular, are to be found in Borghini. Christoforo Sorte[21] (1580) briefly alludes to the subject in question. After speaking of the methods of distemper, he observes that the same colours may be used in oil, except that instead of mixing them with size, they are mixed on the palette with nut-oil, or (if slow in drying) with boiled linseed-oil: he does not mention varnish. The Italian writers next in order are earlier than Vasari, and may therefore be considered original, but they are all very concise. The treatise of Michael Angelo Biondo[22] (1549), remarkable for its historical mistakes, is not without interest in other respects. The list of colours he gives is, in all probability, a catalogue of those in general use in Venice at the period he wrote. With regard to the vehicle, he merely mentions oil and size as the mediums for the two distinct methods of oil-painting and distemper, and does not speak of varnish. The passages in the Dialogue of Doni[23] (1549), which relate to the subject in question, are to the same effect. "In colouring in oil," he observes, "the most brilliant colours (that we see in pictures) are prepared by merely mixing them with the end of a knife on the palette." Speaking of the perishable nature of works in oil-painting as compared with sculpture, he says, that the plaster of Paris (gesso) and mastic, with other ingredients of which the ground is prepared, are liable to decay, &c.; and elsewhere, in comparing painting in general with mosaic, that in the former the colours "must of necessity be mixed with various things, such as oils, gums, white or yolk of egg, and juice of figs, all which tend to impair the beauty of the tints." This catalogue of vehicles is derived from all kinds of painting to enforce the argument, and is by no means to be understood as belonging to one and the same method.