A short web article by Ralph Griswold introducing constraints on interlacement patterns (drawdowns), inspired by Stephen Wolfram's A New Kind of Science. It explains global and local constraints such as balanced cell counts and limited float length, and defines constraint sets and satisfiability. It then introduces neighborhood constraints using von Neumann 5-cell templates, noting that plain weave satisfies one template set, and outlines questions about analyzing patterns and constraint sets, to be continued in later articles.