Most likely because metal is not known to be a very flammable material and can withstand the kind of heat that an oven is potentially able to produce.
Some are but most are made of steel.
metal
oven mitts
heat makes metal expand.
Yes, if the trays are full.
oven trays are the metals found at home.
Because a microwave oven does not target one area of the oven, microwaves are random and a revolving tray captures more microwaves.
The advantage of oven drying method is that all the trays get equal heat and therefore the drying is uniform. The disadvantage is that the dehydrator has limited capacity.
1/4
cheese
Wood is porous and sucks in moisture. Also wood could catch on fire while in an oven.
No, just push one tray, pot or what ever you are cooking with to one side of the oven and the other to the opposite side so the bottom tray can "see" the top of the oven. if the trays are to big to do that half way through your cooking switch the trays so the bottom tray is on the top.
Yes its a good idea, Make sure their is no heating element under the base, in your oven, Otherwise should be fine, I put all my oven trays, upside down, in the dishwasher regularly, Saves a lot of scrubbing,
The enamel trays are used for heat-based cooking (convection, oven, broil) in the Advantium. You can either place food right on it to cook and brown, or place a glass baking dish on it. You can not use the enamel tray for microwaving.