At the foundation of every Foam Flying Factory aircraft is an XPS foam available at Home Depot or other big box stores called FOAMULAR 1/4 in. x 4 ft. x 50 ft. R-1 Fanfold Rigid Foam Board Insulation Sheathing. DOW Chemical produces a suitable alternative in Blue; however, the green version from LOWES is too brittle and is not a suitable alternative.

You will hear a lot about Depron in the production of remote control aircraft, but availability in the United States is lacking for a number of reasons, primary due to the product not meeting building code for fire resistance. The product comes in two colors, White and Gray with their weights being between 81% to 71% lighter than FFF respectively. Some alternatives are on the market as such as Dollar Tree Foam or Flite Test Foam by Adams or in limited quantities / conditions Model Plane Foam. Foam Flying Factory has produced aircraft out of all the above types of foam and only FFF is readily available, strong, and flexible.

It Depends. A high level of detail (LOD) aircraft will weigh more than a low LOD aircraft, all other things being equal. This is because the high LOD will use more foam, more glue, and possibly more servos, etc. all requiring different motor sizes which also results in higher or lower total model weight.

Each functional aircraft needs to exist in a magical zone where LOD, weight, and motor are all in balance.

In aviation the force that counteracts weight is lift, and lift requires either raw motor power through the propeller airfoil (drone), or through the airfoil of the aircrafts wing (sailplane).

In reality, aircraft will use a combination of both to achieve flight. Development of a wings airfoil is critical to how the model will fly and what flight characteristics the model will exhibit.