According to a research report from The Scottish Tartan Museum in Comrie Perthshire Scotland, the Moncreiffe/Moncreiff/Moncrieff "tartan is undoubtably one of the oldest tartans existing and is one known by at least four seperate names: Moncreiffe, Old Grant, Old MacLachlan, and Robin Hood. In January 1974, Sir Iain Moncreiffe of the Ilk,... Chief of the name wrote, 'I took a fancy to an 18th century suit in a red and green diced tartan in the Edinburgh Castle Museum... and decided to adopt it as the Moncreiffe tartan with the red to represent the sacred tree from which we took our Gaelic Surname...'" Since 1974 the Moncrieffes adopted the above sett with the full permission of the 24th Chief of the MacLachlans: Madam Marjorie MacLachlan of MacLachlan. The report further states the tartan is Red and Green -- Any thread count of equal proportions. There are various color differences of the wool used by the many woolen mills in Scotland. Number 963 Moncreiffe Tartan is the official tartan of Clan Moncreiffe Society.
Clan Murray has several variations of tartan with the Murray of Atholl tartan being the basic one. Murray of Atholl was modeled after the Black Watch pattern. Moncreiffes wore the Murray of Atholl tartan until 1972. Because of the long-term affiliation and alliance with the Murray clan, this tartan can still be worn.
Many descendants from Scotland can wear the Black Watch tartan. The Black Watch regiment recruits from the highland area of the Moncreiffe family.
The Moncreiffe of Atholl tartan was approved by the Scottish Tartan Society in 1998. According to the Scottish website, Moncreiffe of Atholl tartan is the first tartan designed by members and voted on using the World Wide Web. The designer, Morag Moncreiff, describes the tartan in this manner, "This design takes the same check as the Murray of Atholl Tartan that Moncreiffs used prior to 1974 but uses the colours of the Lachlan Sett adopted by Sir Iain Moncreiffe. In this way it combines the sentiments of Sir Iain and maintains the strong link to the Murray Clan."