Makes a bright blue mark. Marks can be easily removed with plain water. Instructions: Always test Wonder Marker on a spare piece of fabric before using, making sure the marks remove to your satisfaction. On rare occasions certain dyes in material (dyes containing red in particular) may make marks difficult to remove. 1. Mark lightly on wrong side of fabric. 2. To remove markings, rub gently with a well moistened cloth. 3. Occasionally the mark will reappear when the fabric dries. Simply repeat the process. Caution: Be sure marks are completely removed with plain water before laundering. Some laundry products containing more than 3% sodium hydroxide or more than 5% sodium carbonate may cause the marks to turn a brownish color if they are not removed before laundering. Do not iron over marks before removing as on some materials it will set marks permanently.