The following table compares the main properties of the conventional coatings: Acrylic, Urethane, Epoxy, Silicone and Parylene coatings in relation to the parameters that affect the most the proper function of the electronic and electrical devices.

	ACRYLIC	URETHANE	EPOXY	SILICONE	PARYLENE
PROPERTY
Uniform, very thin, conformal layer	G	G	G	G	E
Low stress, pin-hole free layer	M	M	M	M	E
Dielectric properties	G	M	M	VG	E
Physical strength	G	VG	VG	M	E
Flexibility	M	VG	L	VG	VG
Wear and abrasion resistance	M	VG	VG	L	E
Thermal coefficient of expansion	G	M	VG	L	E
Water absorption	G	G	VG	M	E
Chemical, solvents, fungus resistance	L	VG	VG	M	E
Barrier to moisture, gases, liquids	VG	G	VG	M	E
Adhesion to substrates	VG	G	VG	M	G
Repairability	VG	G	L	M	G
No contaminating ingredients	G	G	G	L	E
Particles immobilization	L	L	L	L	E

The rating used are: E= excellent, VG= very good, G= good, M= moderate, L= low.

* Data from Vitek Research Corp.