Collagen is actually a glycoprotein formed into a triple helix (called a fibril), and is found in as many as 19 different varieties in various tissues in the body.
	Elastic fibers are thin and interwoven with collagen fibers to prevent tearing. Elastic fibers are made of the protein elastin (randomly coiled and covalently bound to form an elastic matrix), and glycoprotein microfibils, formed into a cross-linked network within the tissue.
	Reticular fibers produce an endoskeleton or stroma for soft organs such as the spleen, liver, etc.