Polyethylene microspheres of high sphericity and narrowly graded particle size distribution are used in industrial and scientific applications for process control, diagnostics, and medical device technology. Neutrally-buoyant spherical polymer particles are specifically designed for suspension in fresh water, enabling flow visualization and PIV analysis of fluid flow in a device. It is often advantageous to color code the particles by size to better understand which part of the process the spheres of the specific size were able to pass through, or where the contamination in the process is coming from. Polyethylene is inert to most solvents. Polyethylene microspheres are hydrophobic and need to be coated with surfactant prior to suspending in water or aqueous media.

Some polyethylene microspheres have a strong triboelectric (electrostatic) charge. Black microspheres can be manufactured with paramagnetic or static-dissipative properties. Microspheres in any color can be made neutrally buoyant in water with specific gravity of 1.00g/cc. Most of the grades of polyethylene microspheres meet the specification of >90% in particle size range and >90% spherical particles. High protein binding abilities. Custom color and density polyethylene microspheres can be manufactured by request.