Here are the specifics of the Law regarding the use of Purple Paint. The markings must consist of a conspicuous verticle line at least one inch in width, and at least 8 inches in length, and must be placed so that the bottoms of the marks are not less than 3 feet from the ground or more than 5 feet from the ground, at locations that are readily visible to any person approaching the property; and no more than 100 feet apart. Paint markings may be placed on trees, posts, stones or any other objects that are visible to a person approaching a restricted property.