Wallpapers feature repeating patterns of designs. When hanging wallpaper, you line up each strip, matching design elements printed at the edges of the paper. Some wallpapers, such as stripes, match no matter how you hang them. Some papers are designed so that the pattern matches evenly all the way across from sheet to sheet. Still others are designed so that every other strip or every two strips of paper are different, with the design elements repeating diagonally across the wall. The vertical distance between these repeating elements is known as the drop. Wallpapers with long pattern drops may require more paper for complete coverage around the room.
Unroll the wallpaper onto a table, floor or other flat surface that will allow you to unroll 1.5 or 2 metres (5 or 6 feet) of the paper.
Locate a prominent design element on your paper, which could be a medallion, the largest flower in a floral motif, or any other recognisable feature of your pattern.
Place one end of the tape measure in the centre of this design element. If the element doesn't have an easily recognisable centre, align the edge of the tape measure with the top of the design. Measure to the same point on the first occurrence of the same design directly below the first one. This distance is the pattern drop.
Stripes and solids or nearly solid papers have no pattern drop.