The Army Combat Uniform (ACU) replaced the U.S. Army's venerable Battle Dress Uniform (BDU) beginning in 2005. The ACU incorporates a number of significant design changes from the older BDU, including the use of the Army's Universal Camouflage Pattern and garment details tailored for use with the Improved Outer Tactical Vest. The ACU patrol cap is one of the pieces of soft headgear approved for wear with the ACU coat and trousers. According to Army regulations, rank insignia may be displayed on the front of the patrol cap. The back of the ACU patrol cap features a Velcro tab that accommodates placement of a soldier's name tag, but the rank insignia on the front must still be sewn onto the cap the old-fashioned way.
Locate the position on the front of the ACU patrol cap where the rank insignia will be attached and temporarily pin it into place with one or two safety pins. According to U.S. Army Regulations AR 607-1, the rank insignia must be worn centered both horizontally and vertically on the front of the cap. The patrol cap features horizontal stitching across the front that can help you estimate the vertical center but, unlike the older BDU patrol cap, there is no stitching running vertically through the middle of the cap's front. Measure the location with a ruler or other handy tool, if necessary.
Begin stitching the insignia into place from the lower left-hand corner of the rank device. Use heavy thread that is either olive drab or black and start with a double stitch to firmly hold the insignia in place. Run the stitches inside the insignia, parallel to the border of the rank device. Do not loop stitches over the sides of the insignia and into the cap. Unless you're an expert with needle and thread, looped stitches will look sloppy and may collect negative comments at your next inspection.
Stitch the short sides and both angles of chevron devices. Stitch the sides and top of square or rectangular rank devices. Finish with another double stitch and whip off the thread inside the ACU patrol cap. Leave the bottom of the rank device unstitched so you can easily grab the insignia and pull it off the cap when your command dictates removal of rank insignia from your uniform.
Put on the ACU patrol cap and review your work in the nearest mirror. If the rank insignia is not centered on the front of the cap, pull it off and try again.
Only three or four stitches are needed on each side of a rank device. The goal is to keep the device in place during normal wear, but to allow for quick removal -- without damaging the cap -- when command orders the removal of rank insignia. For duty stateside or in garrison, rank insignia usually can be sewn on more neatly and firmly. In such cases, there's no shame in paying someone with sewing skill to do the job for you.