There is some measure of irony in any historical revival or traditionalist endeavor; it requires doing something self-consciously that was not done self-consciously in the past. But I certainly would rather do something good with a measure of irony than do nothing good at all!
Traditional artists might be placed into categories by how they handle this problem of self-consciousness, and by how strictly they imitate the art of the past. At one extreme are forgers: those who actually purport to make the art of the past. The so-called Spanish Forger is a well-known recent example of a skillful but deceptive artist working in a medieval tradition.
Some distance from them stands the reenactors, who admit the originality of thier work, but otherwise follow old practices as exactly as possible. This describes many of the artists and craftspeople participating in groups like the Society for Creative Anachronism (whose work I truly respect and admire).
Next are artists who are analogous to writers of historical fiction in archaic language; they create art that plausibly might have been created in the past, but differs from anything that actually was. After them are artists comparable to writers of alternate history, who construct language to match; I am reminded here of William Morris, whose English is not exactly an imitation of Caxtonian English. Rather, it is an imitation of what Caxtonian English would be like if the Norman Invasion had never happened, an English with its French vocabulary removed. An artist of this kind creates art that might have been created in the past had the past gone differently.
I once thought of myself as the last sort of artist. The basic concept of my artwork was that it was what a Catholic artist of the twenty-first century would have made had the Middle Ages never ceased. It pretended no ignorance of those real facts of which medieval artists were ignorant (the existence, for example, of microorganisms, Japanese culture, kangaroos or the rings of Saturn), but it ignored all of the drastic changes in religion and philosophy that occurred as the medieval world gave way to the modern. It was an art reflecting an instinctive belief in the prefigurement of the Gospel in history, the vision of God in nature, the sacred significance of words and numbers, the reality of miracles and the truth of Divine Revelation.
What I have come to realize is that this art need not be a work of fiction at all. For the more I learn of the medieval worldview, the more I believe it to be correct. No suspension of disbelief or willful ignorance is needed to believe that every animal, vegetable and mineral in God’s creation; every length, height and depth; every thought, word and act of the past, present and future is charged with a mystic significance. I intend my art to demonstrate that these things can (still and always) be seen from a medieval perspective, which is to say, a Christian and sacramental perspective. The world that we see once the scales of modern misconception fall from our eyes is reality itself; the very world that God made, and in which the invisible things of Him from the creation of the world are clearly seen, being understood by the things that are made.
These different approaches to traditional art require artists to make different decisions about their materials and processes. I am often asked whether I use historically accurate materials and tools to make my drawings. For the most part, I do not. My standard for choosing materials and tools is to use whatever can realize the pictures that I have in mind in the most precise, beautiful and permanent way. This, I believe, is in the true spirit of medieval art. Sometimes, this means using an old process; calfskin vellum is, I believe, the very finest material for drawing, and had real advantages over any modern material which might be substituted for it. But I would not make a drawing in oak gall ink (one of the most common medieval inks) because it is now known to be acidic; rather, I would choose an archival ink that looks similar. Likewise, I would not use silver leaf for illuminated details, as many medieval artists did; silver tarnishes to an ugly black after exposure to air. Medieval artists did not know that platinum-group metals, which do not tarnish at all, existed. Now, palladium leaf is readily available (and not especially expensive), so I use that instead.