Create a single color and contiguous area marker

Hello,

I need to create a marker that must be single color an contiguous (I don't have to print it, but create it physically to use in an inlay).

I've made some tests uploading the test images in attachment to the target manager, and test6 gets a 5 star rating, while test10 get 2 stars (the other designs gets 3 and 4 stars rating).I then simply printed them (size 4cm) and the recognition performs accordingly.

My problem is that test10 would be much easier to realize, so I'd like to create the most simple tracker while still getting a 5 star rating.I understand all the features stuff, and the fact that Vuforia tracks an image... but I wonder why many other augmented reality toolkit I've tested can detect very simple markers, even simpler than test10.

If a frame marker image is uploaded to the target manager, it gets a very poor rating, still is detected very well. Does frame marker recognition and image target recognition use different algorithms?

Any suggestion on which tricks to use to create a better tracker, or on how to configure Vuforia to recognize a very simple tracker.

Thanks,Mattia