一種顏色從亮紅到濃紫的天然染料，取自橡苔屬、染料衣屬、樹花屬、茶漬屬等多種地衣中任何一種，此類地衣曾被埃及人用為染料。苔色素的調製方式在中世紀由義大利人飛德瑞果（Federigo）重新發現並遭其壟斷，被用來製作佛羅倫斯布料中的鮮豔紅色及紫色。十八世紀時，一名蘇格蘭化學家高登（C. Gordon）再重新發現其製造過程並申請專利，稱之「地衣紫」。茶漬酸經發酵再氧化轉化為地衣紫色素，便形成苔色素中的深紅色。苔色素可做為顏料、紡織染料、木材染色劑、食物著色劑，及在鹼性溶液中會呈藍色的指示染料。

苔色素(P,,U,繁體中文-偏好,D,,)
地衣紫(,U,繁體中文-非偏好,UF,U,U)
紅靛青(,U,繁體中文-非偏好,UF,U,U)
t'ai se su (P,,U,韋氏拼音-偏好,UF,U,U)
tāi sè sù (P,,U,漢語拼音-偏好,UF,U,U)
tai se su (P,,U,漢語拼音(無聲調)-偏好,UF,U,U)
archil(P,,U,英文-偏好,D,U,N)
orchil(,U,英文-非偏好,UF,U,N)
cudbear(,U,英文-非偏好,UF,U,N)
red indigo(,U,英文-非偏好,UF,U,N)
orseille(P,,U,荷蘭語-偏好,D,U,U)
orchilla(P,,U,西班牙語-偏好,D,U,U)

藝術與建築詞典根目錄
....材料層面
........材料 (材料層面)
............材料
................<依功能區分之材料>
....................著色劑 (材料)
........................染料 (著色劑)
............................<依構成要素或來源區分之染料>
................................天然染料
....................................植物染料
........................................苔色素

source plant or animal for....

法國紫

英文....

A natural dye that is bright red to rich purple color, obtained from any of several lichens of the genera Evernia, Roccella, Ramalina, and Lecanoria. such lichens were used by the Egyptians for dyes; the preparation of archil was rediscovered and monopolized by Federigo, an Italian, in the Middle Ages. Archil was used to make the brilliant reds and purples in Florentine cloth. In the18th century a Scottish chemist, C. Gordon, rediscovered and patented the process, which he called "cudbear." The dark red color in archil is formed when lecanoric acid is converted to orcein by fermentation then oxidation. Archil is used as a pigment, textile dye, wood stain, food colorant, and an indicator dye that turns blue in alkaline solutions.

苔色素............	[AS-Academia Sinica]
.................	藝術名詞與技法辭典 26, 314
.................	國家教育研究院－雙語詞彙、學術名詞暨辭書資訊網 November 20, 2009
地衣紫............	[AS-Academia Sinica]
.................	藝術名詞與技法辭典 124
紅靛青............	[AS-Academia Sinica]
.................	藝術名詞與技法辭典 375
archil............	[VP]
.................	Mayer, Dictionary of Art Terms and Techniques (1969) 19
.................	Webster's Third New International Dictionary (1961)
.................	MFA Conservation and Art Material Encyclopedia Online (2005-) accessed 10 March 2009
.................	Oxford English Dictionary Online (2002-) accessed 10 March 2009
.................	AATA database (1995-) 126833 checked 26 January 2012
orchil............	[VP]
.................	American Heritage Dictionary (1969)
.................	CDMARC Subjects: LCSH (1988-)
.................	Mayer, Dictionary of Art Terms and Techniques (1969)
.................	Encyclopedia Britannica Online (2002-) accessed 10 March 2009
cudbear............	[VP]
.................	Mayer, Dictionary of Art Terms and Techniques (1969) 19
red indigo............	[VP]
.................	Mayer, Dictionary of Art Terms and Techniques (1969) 19
orseille............	[Bureau AAT]
.................	AAT-Ned (1994-)
orchilla............	[CDBP-DIBAM]
.................	Diccionario de términos científicos y técnicos (1981) 5:2602
Subject:............	[Bureau AAT]
.................	AATA database (1995-) 126833 checked 26 January 2012
.................	Van Dale Engels-Nederlands (1989)

Getty AAT: 300013066 Getty AAT: http://www.getty.edu/vow/AATFullDisplay?find=costume&logic=AND¬e=&subjectid=300013066
聯合目錄： 苔色素 、地衣紫 、紅靛青 、t'ai se su 、tāi sè sù 、tai se su 、archil 、orchil 、cudbear 、red indigo 、orseille 、orchilla