Looking at the metapost examples in the Wiki it appears that a block symbol can be defined or redefined which allows the size of the block to be changed. Does this apply to each instance of a block or is it a global definition. How do you specify the size of the block when you place it in the drawing? code metapost def p_blocks_UIS (expr pos,theta,sc,al)= symbolsize:=1.0u; %Factor*u; Factor=size of the blocks U:=(.5u,.5u); T:=identity aligned al rotated theta scaled sc shifted pos; pickup PenC; thdraw (.0symbolsize,.0symbolsize)--(1.0symbolsize,-. 5symbolsize)--(0.0symbolsize,-1.5symbolsize)-- (-1.0symbolsize,-1.0symbolsize)--cycle; thdraw (.5symbolsize,-.25symbolsize)--(1.0symbolsize,. 5symbolsize)--(0.0symbolsize,1.5symbolsize)--(-0.5symbolsize,. 5symbolsize); thdraw (.0symbolsize,.0symbolsize)--(.0symbolsize,.5symbolsize)-- (-1.5symbolsize,.5symbolsize)--(-1.5symbolsize,-0.5symbolsize)-- (-0.5symbolsize,-0.5symbolsize); enddef; endcode Dave Clucas email:dave@daveclucas.com Website: http://daveclucas.com http://mycaves.org Skype: daveclucas