sizing vs filler

sizing and filler both are nouns.

Word	Noun	Adjective	Verb	Adverb
sizing	Yes	No	No	No
filler	Yes	No	No	No

As nouns, filler is a hypernym of sizing; that is, filler is a word with a broader meaning than sizing:

sizing: any glutinous material used to fill pores in surfaces or to stiffen fabrics
filler: used for filling cracks or holes in a surface

sizing (noun)	filler (noun)
any glutinous material used to fill pores in surfaces or to stiffen fabrics	the tobacco used to form the core of a cigar
	anything added to fill out a whole
	copy to fill space between more important articles in the layout of a magazine or newspaper
	100 filler equal 1 forint in Hungary
	used for filling cracks or holes in a surface