Getting the poo 
We started our journey cycling, as we do in the Netherlands, to the Nature Farm Hardebol  
just outside of Amsterdam. We wanted to meet the local cows and ask them if we can borrow some 
manure. They said yes, so we put on our boots and cow shorts and collected some fresh  
cow dung. The farmers were friendly and quite intrigued by the project.  
Material characteristics     
First, we became familiar with the properties of manure: it is very lightweight,  
cellulose based, negatively charged, hydrophobic, and dependent on the diet of the cow. 
To find the best possible recipe, we did some literature research and talked to experts about   possible fillers and binders, and the ratios at which they could best be used.   
Formulating filament recipe 
Then we went into the kitchen to experiment with the 3Dprinting filament. We've tried  
out approximately 35 different recipes to create a paste that is viscous but also strong when dried. At this stage, we printed the paste manually with various nozzle sizes and layer heights. After letting the samples dry for 5 to 7 days, it was time to test the strength, water and fire resistance. A building material has to go through a lot of regulations concerning these characteristics, so it was important for us to know.  Although we didn't have the means to get some hard data on these characteristics, the results we have found are promising. From this process, we selected three recipes that filled all these criteria the best and that we wanted to test in a paste printer. 

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