Definition of "shuttering"

In the long run, Marvel's B&W newsstand efforts outlasted the closing and shutterings of both Skywald and Warren's doors but the longest lived of their horror titles only lasted two years, from 1973–1975.

2013, Richard J. Arndt, Horror Comics in Black and White: A History and Catalog, 1964-2004

[I]n practice, small deformations will occur in the shell on striking the shuttering, or... alternatively, some small deformations are due to slightly imperfect placing of the original formwork.

1977, Jaques Heyman, Equilibrium of Shell Structures, Clarendon Press, Oxford, page 107