For instance, consider the example sentence in the graphic above. Using the modifying suffix -size (as well as its sibling -sized) is colloquial and as such conveys that informality which more effective technical writing omits.
Both -size and -sized are very common in advertising copy, in which people write very much like they speak. Technical writing is a very different game. More effective technical writers will opt to omit -size and -sized from their writing to avoid too much informality.
Redundancy provides another rationale for omitting -size and -sized. Consider this revision of the example sentence in the cropped graphic above.
You could make an exception if -size and -sized are part of a name. In that case, they are an essential part of the proper noun and should not be removed. In all other instances, these suffixes are redundant and should be avoided.
So remember to downsize your use of -size and -sized. Avoid colloquialisms and redundancies in language. Such efforts will produce not only more effective technical writing but also more effective presentations of both you and your brands to your audience.