[Clipart] Patterns: how to avoid gaps at the edges

[Jonadab the Unsightly One]

I've made my first forray into patterns, and I have a question:

How do I prevent the pattern from having slight gaps in the edges?
You can see my first attempt here:
http://openclipart.org/incoming/lindworm_snake_jonadab_t_01.svg

If you zoom in a bit, you'll notice that the skin pattern has
horizontal and vertical gaps in it, where the underlying color (from
the shape(s) beneath) shows through plain.  But I noticed that Alan
Horkan's patterns do not have this problem, so obviously there's
something I'm doing (or not doing) that causes this.  What is it?

-- 
$;=sub{$/};@;=map{my($a,$b)=($_,$;);$;=sub{$a.$b->()}}
split//,"ten.thgirb\@badanoj$/ --";$\=$ ;-> ();print$/