Early Origins
The Catholic Encyclopedia suggests that the origin of the antipendium might be "traced to the curtains or veils of silk, or of other precious material, which hung over the open space [NLM note: or "confessio"] under the altar, to preserve the shrines of the saints usually deposited there" which later developed into the altar frontal we now know.
In his work, The Christian Altar, the Anglican Cyril Pocknee notes that "even in the primitive period not only was the altar covered with a linen cloth or pall for the celebration of the Eucharist; but also the Lord's Table was vested with silk cloths... Palladius writing about 421 mentions some Roman ladies, who renouncing the world, bequeathed their silks to make coverings for the altar... The Liber Pontificalis testifies that during the eighth and ninth centuries coverings for the altar made of gold thread and decorated with jewels and pearls and embroidered with figures of our Lord, the B.V. Mary and the Apostles were given to the great Roman basilicas by succeeding Popes."
Pocknee speaks to the development of the form as follows:
While the altar remained cubical in form, the 'throw-over' type of pall continued in use... this linen cloth, known as the Palla corporalis, was thrown over the altar, much as an ordinary table-cloth is spread today, by the deacons, and it fell down around all sides of the table. But in the Gothic period, when the altar tended to be lengthened, two things happened: (a) the linen pall became divided into two parts, one part being a long strip which covered the top of the altar and fell down over each end of the mensa, while the other part became the 'corporal' which covered the elements; (b) the silk pall becomes the antependium or frontal covering the front elevation of the altar only when it stood close to a wall or screen. But it should be noted that where the longer type of altar was free-standing a 'frontal' was provided for both back and front.
Both Cyril Pocknee (The Christian Altar) and J.B. O'Connell (Church Building and Furnishing) comment that the earliest frontals were "often made in purple and gold and ornamented with jewels, or with beautiful embroideries." (O'Connell). The following image from the Benedictional of St. Ethelwold shows this, as well as what Pocknee describes in terms of the fuller, more "table-cloth" like form of the early altar covering:
O'Connell continues by noting that in the 8th or 9th centuries, some frontals were also made of precious metals such as silver or gold. A classic example of this would be the altar of the Basilica of St. Ambrose in Milan:
It was during the middle ages that we begin to see the vesting of the altar match the colour of the vestments of the day.
Symbolism
Speaking to the symbolism attributed to the frontal, Geoffrey Webb in The Liturgical Altar calls it "a covering of honour for the body of the altar which... represents Christ Himself..." He quotes Bishop J.F. Van der Stappen in his work, Sacra Liturgia as saying: "For the altar is Christ, therefore, on account of its dignity, it is clothed in precious vestments, as the Pontifical says in the ordination of sub-deacons." Webb continues speaking of the colour that the frontal brings to the altar: "Our Lord, as represented by His consecrated altar, puts on robes of majesty... and when the Robes of Majesty are all removed on Holy Thursday, more is indicated than the removal of His garments. His faithful, His costly garments, His disciples, are all stripped from Him; and His desolation is made all the more evident by this complete annihilation of colour." The use of colour is "part of the splendour of the liturgy" but "the instinct to provide colour seems less vigorous today than in most other centuries, and one doubts whether its place is sufficiently realized as one instrument of a concerted orchestra, in whose harmony its omission forms a gap." Finally Webb suggests that "the frontal serves to give to the altar that architectural prominence which its central position in the liturgy requires."
O'Connell notes similarly:
"...at the ordination of a subdeacon, the bishop in his charge to the candidate says 'the cloths and corporals of the altar [which represent Christ] are the members of Christ, God's faithful people, with whom, as with costly garments, the Lord is clad, according to the Psalmist: The Lord reigns as king, robed in majesty.' The clothed altar with its beauty and changing colours is a symbol of the Mystical Body... it translates this doctrine into the language of colour and form. In addition to its symbolical value, the frontal -- with its sequence of colours and its changing form and decoration -- lends variety and new beauty to the altar, and helps to mark the degrees of festivity in the Church's liturgy. In presenting an unbroken coloured surface it also draws attention to the altar, as the focal point of the church, giving it architectural prominence."
A visual comparison of the altar of St. Peter's Basilica, unvested and vested, might serve to illustrate the visual and liturgical difference a frontal can make.
An NLM Appeal for the Revival of the Altar Frontal
The NLM has often appealed to clergy to consider re-instituting the use of altar frontals in their parishes and apostolates. It is to be hoped that these descriptions of the history and symbolic and liturgical value of the frontal will serve as further inspiration.
Now this said it must be stated that, as with any sacred arts, not all frontals are created equal. In my experience, the finest frontals are characterized by neatness, not hanging too loosely (being either stretched onto a frame or at very least of heavy fabric and generally weighted), thereby drawing attention to the form and substantiality of the altar itself; they cover the entirety of the front of the altar, and they are characterized either by a verticality in ornamentation, or a fullness of ornamentation. (What I mean by this will become more evident shortly.)
Examples of Unsuccessful Frontals
Let us consider a few examples of what I would deem unsuccessful attempts at altar frontals.
There are a few problems here. First, the use of a single colour without other ornamentation or orphreys. But worse is the use of pleating which takes away from the altar itself and approximates not so much paraments for the altar as curtains before it.
This frontal's ornamentation is rather plain and could be much improved by being weighted better and by including a greater vertical dimension in terms of its decoration.
Two different forms of a kind of "superfrontal" which only partially covers the altar. The former might also be manifest by the use of a Jacobean style altar linen in which coloured strips are hung down in front, over part of the altar.
While both are quite neat, neither of them seem to accomplish the dignified vesting of the altar, nor create the focus upon the altar that a full frontal accomplishes.
Here is another example of this sort of less than edifying attempt at a frontal, but quite a bit less neat:
Our next example is likely to be the most controversial in my proposal about what is not successful; it is the Laudian frontal:
This form, which finds itself draped over the entire altar, certainly approximates some of the earlier form of the altar covering discussed in this history, however, this form of frontal seems to lack the neatness and elegance of the frontal as it developed. It must also be remembered that the original forms related to the cube shaped altars of the earlier Church and not to the longer altars that developed.
A final example of a less than successful attempt:
Successful Frontals
Now let us compare the former examples with altar frontals that better serve to vest the altar in a dignified manner, drawing attention to it and to the liturgical seasons. I have tried to include stylistic variations to show the range of possibilities.
(Image source)
(An unfortunate aspect of this image is the altar linen hanging before the frontal, but ignore that for the sake of the fact that our attention is purely focused upon the frontal design)
While I imagine there will be some disagreement about some of the principles behind the comparison of what is successful and what not, my ultimate hope is that this exercise might serve as the basis for a more considered approach to the altar frontal in a way that gives thought to their purpose and how they might be most liturgically dignified and effectual.
UPDATE
There has been some discussion and questions about the making and hanging of frontals. Here is what O'Connell notes in Church Building and Furnishing:
Material of the Frontal
[...] The frontal is best made of some textile -- because it is part of the clothing of Christ -- brocade, tapestry, velvet, silk, damask, etc.; or more simply for lesser days, or in small churches, with orphreys of silk, or with braid or fringe. Designs should be bold since the frontal is viewed from a distance. In the traditional Roman frontal the material is divided vertically into panels (generally five) by narrow strips of braid; across the frontal (about one-fourth of its depth from the top) is a deeper strip, and the upper part of the frontal above this is divided into twice the number of panels (normally ten) by braid or galloon. The frontal may be adorned with woven or painted figures or scenes, or with suitable symbols (e.g., of the Blessed Eucharist).
[...]
Fixing a Frontal
The frontal must cover the entire front of the altar. It may be fixed on to a wooden frame (telarium)... which slips into a groove under the table of the altar [NLM note: I have also seen peg like objects which the frontal inserts into and then it further tied to the sides of the altar with to hold it tight against the altar; this is the case at Ss. Trinita in Rome]; or it may hang, by small rings, from a rod, supported on metal lugs in the front elevation of the altar. The rod and its attachment are concealed by a frontlet [NLM note: or "superfrontal"; it is the short but long rectangular piece that hangs across the top foot or so of the front of the altar, also the section which was referred to above as having double the panels of the lower half; this is the arrangement at the chapel of Merton College, Oxford]. It is sometimes desireable to back a frontal with some heavy material, like strong canvas, to get it to hang well.
