1352 express] Clark & Wright (ed. 1872): “exact, fitted to purpose, as the seal fits the stamp. So in Hebrews i. 3. ’express image’ is the rendering of the Greek ( )."
1351 forme and moouing] Wright (1981, p. 185 n. 20): “Although the two nouns could be taken separately, they seem more effective in combination: ‘in his form, and in the movements of that form.’ It would seem more appropriate to describe the movements of the body as ‘express’ than to speak so of the body at rest. The word moving sets the idea of form in motion.
“Most editors have felt some anxiety about express. Several gloss is as ‘exact,’ one as ‘well-devised,” another as ‘well-framed (?).’ Rylands suggests ‘active, purposeful, or well-modelled (Lat. exprimere, to portray).’ Kittredge offers ‘precisely adapted to its purposes—like a delicately adjusted piece of mechanism.’ (He does not say what mechanism—a Swiss watch? the 3:18 to Stratford?—Shakespeare may have had in mind.) But most of the OED’s meanings for express emphasize the idea of distinctness: clearly outlined, sharp, definite, explicit. So ‘how express and admirable’ probably means ‘how admirably distinct, how wonderfully clear and sharp in the articulation of its form’.”