Urushi is the sap from the Urushi Tree, rhus vernicifera, which is related to the poison ivy plant because the tree's sap contains an oil, urushiol, which can cause an allergic reaction, typically a rash. (Urushi, 2016)  When using urushi, it is suggested that non-latex gloves, long sleeve shirt, respirator, and safety glasses be worn to reduce the chance of coming in contact with the urushi.  While I was using the urushi, I wore only the non-latex gloves and long sleeve shirt and still managed to get a rash. 

   The following process for using urushi, on armor, can be found in The Manufacture of Armour and Helmets in Sixteenth Century Japan, by Sakakibara Kôzan.  It is an 11 step process which was used to finsh the surface of armors during and before the 16th century.  I started learning how to use urushi by starting with a small 16ga steel test plate.  Urushi, when applied to armor, was used on both steel and nerigawa (a flexible and semi-translucent rawhide).  The armor was also finished both outside and inside, although the inside did not have as many layers as the outside (only 8 layers) as a lining was installed which covered the inside of the armor.  This is just a very basic understanding of the process of using urushi.  There are many more urushi recipes, that I do not know, which create the different surfaces and textures on some armors.  The recipes used here can be found in the references.

   Process:
     Plate Prep:  The steel plate, 18ga, was prepped by sanding the surface with a coarse sanding disc on a grinder.  The period way would have been done with a coarse whetstone, leaving the hammer marks in the surface of the steel. 

      Layer 1:  Ko-Ita-Nuri   A single thin layer of Seshime-urushi (twig lacquer).  I attempted to make the layer as thin as possible, to the extent of scrapping the lacquer off the plate, so it looked as though there was not enough urushi to be of any significance to the process.  I allowed this layer to cure in a Muro (curing cabinet) for 2 days.  After curing, this layer is sanded smooth to prep it for the next layer.



      Layer 2:  Mugi-Urushi   A mixture of wheat flour (mugi-ko) and seshime-urushi.  The mugi-urushi is laid over a covering of cloth.  The cloth is a complete overlay, meaning, it covers both the front and the back of the plate.  For the test plate, I only covered the front of the plate.  I also used a thin layer of the mugi-urushi to hold the cloth in place before appling the mugi-urushi on top of the cloth.  Seemed to make sense, as the cloth would have moved around too much if I just applied the mugi-urushi on top of the cloth.  I  allowed this layer to cure for 2 days in the muro.  After curing, this layer is sanded smooth to prep it for the next layer.



      Layer 3:  Kokuso   This layer is used to fill in any uneven spots on the armor's surface.  A mixture of chopped hemp, wheat flour, and seshime-urushi is used for this purpose.  Since the test plate was flat, I did not feel that I needed to do this layer.  If this layer is used, then it needs to cure in the muro for 2 days.  Once cured, it is sanded smooth to prep it for the next layer.



      Layer 4:  Seshime-Nuri   A thick layer of seshime-urushi is applied to give the cloth layer a smooth surface.  I applied just enough seshime-urushi so the surface looked even.  I allowed this layer to cure in the muro for 2 days.  Once cured, it is sanded smooth to prep it for the next layer.



      Layer 5:  Sabi-Nuri   A mixture of seshime-urushi and Tonoko (clay), is applied in a thin layer over the surface.  I applied as thin of a layer as I could.  I then allowed this layer to cure in the muro for 2 days.  Once cured, it is sanded smooth to prep it for the next layer.



      Layer 6:   Sabi-Gatame-Nuri   This layer is a repeat of Layer 5.  I allowed this layer to cure in the muro for 2 days.  Once cured, it is sanded smooth to prep it for the next layer.



Now the Finishing layers are done.

      Layer 7:   Ro-Iro   A thin layer of Kurome-Urushi (Black Lacquer) is applied.  This layer is the base layer for all the finish layers, and I applied it as thinly as possible.  I then cured it in the muro for 6 days.  Once cured, this layer as sanded smooth ro prep it for the next layer.  This layer needs to be as smooth as possible. 



      Layer 8:   Ro-Iro   Same as Layer 7.  I allowed this layer to cure in the muro for 6 days.  Once cured it is sanded smooth to prep it for the next layer.



      Layer 9:   Ro-Iro   Same as Layer 7.  I allowed this layer to cure in the muro for 6 days.  Once cured it is sanded smooth to prep it for the next layer.



      Layer 10:  Ro-Iro  Same as Layer 7, except, after this layer is cured for 6 days, it is polished with charcoal powder and calcified deer horn.



      Layer 11:  Ro-Iro   Same as Layer 10.  After curing for 6 days, this layer is polished the same as the previous layer.  Once this layer is finished, it should have a dull black appearance, which is preferable.  According to Sakakibara Kozan, armor lacquered as described above will withstand soaking in water for months at a time; it will not easily chip, nor will its apperance be affected by cold or hot weather.