input plain_ex; beginfig(0); thick:= 12; thin := thick*0.4; vardef thick_nib = fix_nib(thick, 0, 0) enddef; vardef terminalnib = fix_nib(thick, thick*0.4, 0) enddef; path paths[], strokes[]; m:=100; z0 = (0, 0); z1 = (x0-m/3, (y0+y2)/2); z2 = ((x1+x3)/2, m); z3 = (x1+m, y1); z4 = (x3-m/3, y0); paths[0] = z0..z1..z2{right}..z3..z4; pen_stroke( nib(terminalnib rotated 0)(0) nib(thick_nib)(1,3) nib(thick_nib scaled 0.8 rotated 90)(2) nib(terminalnib)(4) )(paths[0])(strokes[0]); draw strokes[0] withcolor 0.8white; fill strokes[0] withcolor blue; clearxy; z0 = (xpart point infinity of paths[0] +thick/2, thick/4); z1 = z0+ (3/4m,0 ); paths[1] = z0..z1; pen_stroke( cut(terminalnib rotated 90, 45)(0) nib(thick_nib rotated 90)(1) )(paths[1])(strokes[1]); draw strokes[1] withcolor 0.8white; fill strokes[1] withcolor blue; clearxy; z0 = ( xpart point infinity of paths[1] , -thick/4); z1 = z0+ (0, m ); paths[2] = z0..z1; pen_stroke( nib(thick_nib scaled 1.2)(0) nib(terminalnib)(1) )(paths[2])(strokes[2]); draw strokes[2] withcolor 0.8white; fill strokes[2] withcolor blue; endfig; end