what is the appropriate dress code

The primary and foundational clothing of a Mason is the white lambskin apron 1. Essential to its symbolic character are its white color, denoting purity and innocence, and its material of lambskin 21.

Specific regulations regarding the ornamentation of the apron vary by jurisdiction and degree:

Basic Lodge Attire: Under standard regulations derived from English usage, an Entered Apprentice wears a plain white apron 1. A Master Mason’s apron is fourteen by twelve inches, made of plain white lambskin, and may be adorned with sky-blue lining, blue edging, and three sky-blue rosettes 1. No additional colors or ornaments are permitted for Master Masons unless they are lodge officers or past officers 1.

Jurisdictional Variations: European and international grand lodges display significant variations. In Scotland, private lodges may choose their own colors and embellishments, and their aprons feature circular flaps rather than triangular ones 1. In Ireland, members often wear simple cotton aprons with blue edging for ordinary lodge meetings, reserving lambskin aprons edged with ribbon and silver braid for annual festivals 1. German aprons vary in shape—square, rounded, or shield-shaped—and may feature levels or rosettes 1. Historically, jurisdictions in France, Italy, Spain, and Greece employed elaborate painted or embroidered satin aprons with crimson, green, or blue edgings and accompanying sashes 1.

Formal and Historical Dress: For public processions, specific dress codes were historically mandated. For example, during an 1841 public procession in New York, Master Masons were instructed to wear a dark coat, white vest, pantaloons, gloves, black hat, black stock, white apron trimmed with blue, and a blue sash over the left shoulder 1. In older Irish practice, Worshipful Masters customarily wore a top hat and a red cloak during lodge meetings 1.

In English Craft lodges, allowable regalia is strictly limited to authorized Craft and Royal Arch jewels, including officer, past master, founder, and charity jewels; all other jewels are prohibited 1.