This goes along perfectly with a robot costume, and was made in collaboration with this robot.
Credit to fungus amungus for the original idea. He claims to have created full-on shiny pants, a more difficult version of these leg coverings. I first attempted to make pants, but the upper part of the pants is very difficult without a pre-made pants stencil and these space pants tend to get very warm. So I opted to just make the legs, which are versatile enough by themselves plus much easier to make and cooler (in both senses!).
*Note: they only look like they belong in space. Don't actually use them in space.
Step 1: Materials
An emergency blanket. It's pretty standard as part of a first aid kit (though you'll want to replace it if you take it from one). It should be extremely shiny silver. It comes in a very small package but unfolds into a pretty expansive thin blanket.
Blue tape or other not-so-sticky tape for temporarily taping down the blanket.
Tape measure or equivalent measuring device.
Your leg. To use as a reference.
Sharpie or equivalent writing utensil.
Step 2: Measure Your Leg
Then measure the distance from that part of your leg to the ground. Add 1-3 inches for the same reason.
Step 3: Cut Out Your Legs
Step 4: Tape the Legs
On the first, tape the two longer edges together with the packing tape. Packing tape will stick very easily, so be careful. It helps to use small pieces. Tape one edge first and then take the untaped edge and bend it over so it sticks to the tape. Do this all the way down the leg.
Repeat this with the other leg.
You should now have two "tunnelly"-looking things. For reinforcement, tape one end of the "tunnel" on each one. This will make sure the top won't rip when you put it on.
Step 5: Turn the Legs Inside Out
Step 6: Try Them on for Size
If your leggings are too small, you're out of luck. You'll have to try again--it's too hard to enlarge the leggings after taping.
If your leggings are too big, fold the excess material at the top over itself until it fits snugly and tape. You may have to remove the leg coverings to perform this taping, though. You're done when they stay up by themselves.
If your leggings fit perfectly and stay up by themselves comfortably, you're done! Proceed to next step.
Step 7: Wear Them
They can be worn over other pairs of pants or they can be worn underneath shorts. Beware, though: fungus amungus warns that without a thin layer between the skin and the legging, you might be uncomfortable.