Why is that bad? Firetacks are pinned to the bark of the tree and if that is soft, well they tend to fall off. If they don't fall off they might turn and that changes the visibility. The second thing is that some of you want to create a "day-cacher-proof" nightcache. Just have a look at the picture below:
|Firetack at Glow-worms and fireflies cache|
If you actually don't care about your reflector being found in daylight or you want to cover some distance, then a cateye might be a good choice. Yes the stuff you normally put on the wheels of your bike and they come in all kinds of shapes and colors. For a kids nightcache they are fun but even better if you want to get the attention of some cachers: You can combine them and create a really large cateye which can be found from very far away. I did place a cache where you had to find the reflector from a lookout. The covered distance was about 1.2 km. In order to find that thing a Maglite 3D and a binocular was all you needed.
|simple white cateye ...|
|... which easily can be seen|
That said you'll wonder what kind of reflectors are really useful for a normal nightcache. Since I am an engineer, self-made is my answer :o) First get yourself some retroreflecting self-adhesive foil. That shouldn't be too hard since some bike-shops have it or the local commercial vehicle design shop or simply a webshop. I've tried a lot of different brands and types over the years and in the end my choice is the black 3M foil:
|Helmet without light|
|Helmet with light|
|close-up of the foil|
- the tube - which is a small plastic tube on which you apply the foil. Just paint it black or whichever camo you like and hang it into the tree with a fishing line. Since it's round it can be seen from different angles.
- the plaque - is a piece of sheet metal. I use that all the time because you can just punch the coordinates for the next stage right onto it. You can also screw it to any kind of object you like and if you use torx-srews it's quite muggle proof as well.
|simple plaque reflector with two torx screws|