The phrase "are printed by a" is correct and usable in written English.
It can be used when describing the action of printing something by a specific entity or individual.
Example: "The documents are printed by a professional printing service to ensure high quality."
Alternatives: "are produced by a" or "are generated by a".
Tufted carpets are printed by a process designed to ensure good penetration.
The widely distributed road maps noted earlier are printed by a few large producers who, in cooperation with others, compile the maps.
Ewww! Well the books are printed by a company called Clays, who have been making books since 1817 and currently produce around 140 million books a year (that's 3 million books a week; that's half a million books a day; that's 20,000 books made by one machine in one hour – phew!) Making books is really a very simple process.
The base and fingers of the gripper are printed by a 3D printer (Objet350 Connex3, Stratasys, USA) which can print soft material.
After the sale is complete, the shirts are printed by an Amazon-owned printer and shipped to customers anywhere in the world.
It was printed by a friend who was a graphic artist.
The pictures were printed by a national newspaper after Rooney joined a wedding party following England's World Cup qualifying victory against Scotland.
But in the 16th century, the first complete editions of the Talmud were printed by a publisher from Antwerp, Belgium; the Vilna edition, printed in Lithuania in the 19th century, standardized pagination.
In most countries, the colophon now appears on the page opposite the title page and consists of a one-sentence statement that the book was printed by a given printer at a given location.
This country has the most draconian libel laws in the free world: if a damaging untruth really has been printed by a paper, why not send a lucrative legal letter instead?
