Make a safe cup. No amount of water will do you any good if you get sick (or die) from unseen microbes (bacteria, viruses, etc.).
Make sure the material you will use to make your cup is sanitary. If no pre-treated polymer flexi-sheets are available, make sure
to sanitize (by heat or chemical treatment) the material appropriately. Alcohol compounds are usually adequate where heat cannot
be used. If natural materials (such as large leaves) are necessary, please pay particular attention to the following instructions.
Leaf cup success can be increased if the leaf:
o Is relatively large
o Has a waxy coat (provided it is not toxic or water soluble; “See Pamphlet 6298: Common Characteristics of Toxic Plants” to
help you choose a safe leaf and always study the local fauna before your mission.).
o Possesses long, transverse veins
o Is thick and pliable
Lay the material lengthwise (which will comprise the sides of the cup) and ensure there are no holes or other structural deficiencies
that may render the cup porous. Things to look for include:
o Bug holes
o Dry, weather-worn or inflexible sections
o Ample width to fold the bottom of the cup
o Ample length to offer a 10-25% (ideal) overlap to the leading edge of the cup
o Additional material to use as a sealant
Roll-fold the leaf to form the body of the cup.
Complete the cup by folding its bottom (using one of these two techniques):
o If the leaf is of adequate size, fold multiple times (across the bottom, then again in a perpendicular fold to the original) and
seal. This is the preferred cup bottom as all sealant material is kept out of contact with the water.
o If a conical bottom is not possible, a single seam is a viable alternative (provided an appropriate sealant is available). Use
as little sealant as possible to prevent possible contamination.
Avoid unnecessary movement and keep the water as “still” as possible in the cup.
Avoid drinking the lower third of the liquid (which may be contaminated by any non-sterile or unknown sealant).