silver tarp on top with blue on the bottom

[JettBurner]

I have a tarp thats 10mil think and its silver on top and blue on the bottom... I know ive read in the forums NOT to bring the blue tarps... BUT common sense says its silver on top which should reflect the sunlight away...I dont know...thoughts please? virgin burner quite excited for this trip, trying to make sure my tent has some shade.

[theCryptofishist]

Okay, the thing about blue tarps is less about the quality of the shade, and more about the quality of the material. There's a very common blue tarp that, when exposed to uv light for very long, sort of shreds, as if it had had a social security number on it and needed to be destroyed.
There's a very distinctive texture to them. If you've ever seen one of those big blue bags from IKEA, you know the stuff.

[TomServo]

While it's not Heavy Duty, it should be fine, shade wise. Like fishy said, feel it and see if it feels like a dog food bag. If not, use it! Regardless, you might want to reinforce the grommets with Nashua Duct Tape or Gorilla Tape as shown...excuse the "blue" tarp in the pic..I made it blue to stand out against the tape...

[Sham]

I have used a light weight blue tarp under my tent for many years. If you do this, be sure that it completely tucks just under the tent, so if it rains, the water will not well up under your tent, but instead, will hit the ground and keep you dry. I also use a heavier blue tarp for my water retention and evaporation pond. As far as shade, the silver/brown tarps are the way to go.

[Canoe]

... BUT common sense says its silver on top which should reflect the sunlight away...

Quality varies on the "silver". It should be aluminized mylar/polyester. It's a good radiant barrier. It reflects away around 90% of: the sunlight, heat in sunlight, and heat radiated from the hot ground and hot air. This will degrade as it blows in the wind and gets crinkled, but it is still worthwhile for reflecting heat away. As it gets coated with playa dust, that dust will block the reflection and will absorb heat, which will be conducted to the blue side and radiated at you. Give it a quick wipe now and then if you notice it's not working as well.
The underlying blue tarp is not robust. If it survives the week, watch out for trying to make it work again next year.