Deeper Meaning of the Masonic Apron
Entered Apprentice Apron
The flap of an apron turned up appears as a triangle surmounting a square, the square being the lower portion of the apron. In this position it symbolizes the "two" men separated. The square below is the material man with no spiritual part. The triangle above represents the spiritual, hovering over, but not yet having entered the material. In evolution it depicts the "brute-man" before the advent of the spiritual, which we term the dawn of conscience. The ancients' axiom: "As above, so below" is recalled. What is the counterpart "above" of this symbology? It is the story of creation. The triangle, or flap, is the Spirit of God, hovering above the waters (the material) from which He is about to manifest the material universe.
George Steinmetz, The Hidden Meaning of Freemasonry (Macoy Publishing 1980), p. 65
Fellowcraft Apron
No longer "a bearer of burdens," the Fellow-craft need not wear his apron to protect his clothing. He has departed from the material; he no longer need bear burdens. The candidate represents man rising, in the process of evolution, from the level where he was dependent on the brute-force of his physical body, to the use of his mind. Mind being creative, he may now, to the extent of his knowledge, create his own conditions. He wears his apron in a manner to symbolize this fact.
All aprons seen in Lodges are not properly made; some are slightly oblong. The correct specifications would call for a perfect square of approximately fourteen inches, surmounted by a triangle whose base is the exact length of one side of the apron and whose apex forms a ninety degree angle. When the flap is turned down it should appear as a triangle within a square. This symbolizes the spiritual within the material. Hereby man begins the evolution which will eventually end in his assuming the likeness of his Creator. Thus the symbology of the apron repeats and verifies that of the Square and Compasses.
Steinmetz, p. 106
Master Mason Apron
The manner of wearing the apron in the preceding degrees is recapitulated. A certain manner is both described and demonstrated, and the Candidate is then informed that it is "obsolete" because of certain reasons, and that the apron should be worn as a Fellow-craft.
An apron folded diagonally not only does not form a square (as stated in several jurisdictions in America) but loses all resemblance thereto—it becomes a triangle. It is the emblem of the spiritual, and concurs in the symbology of the compasses elevated above the square. For the sake of consistency, in view of the fact that the apron and the square and compasses have repeated the same progressing symbology thus far, it may be asked if a further change in the apron is indicated. It is impossible to fold an apron, evenly, into an equilateral triangle; it therefore will not change to concur with the symbology of the six-pointed star. The apron is worn by the evolving man, up to and including his attainment of "completeness." But the apron is a material thing, regardless of what it may symbolize; obviously it cannot be worn by the perfected man, who is a spiritual being, hence logically the progression of the apron ceases.
Steinmetz, p. 153

