Diaper method - is a method of mixing chemicals that are friction sensitive. Compositions that are friction or shock sensitive should never be rammed nor be passed through a screen.  Mixing via diaper method is usually done by laying a piece of newspaper on the ground and pouring all the chemicals into the centre of the sheet. Taking one corner at a time you lift the paper and roll the composition into itself. Alternate corners of the paper until the composition is fully mixed. The most common pyrotechnic composition mixed via the diaper method is flash powder due to it's high shock and friction sensitivity.