I need to find a mesh material through which is going to be easy to make a nice bulge , but it should stay in that state(not flexible)…please help!!
What type of mesh are you thinking of? Metal mesh? Fabric Mesh?
For fabric, you could look at some mesh materials that can be vacuum/ thermoformed against a harder substrate like another thermoformable piece of plastic (IE Acrylic)
Aluminum mesh? Plastic Mesh? Steel Mesh?
Sadly, the word bulge always brings to mind David Bowie in the movie Labyrinth:
You need to provide a better description.
If fabric, wet the mesh with a hardening resin, squeeze it out, form it and let it cure.