MILWAUKEE - Industry giant Bemis Manufacturing Co. isn't about to take toilet-seat misrepresentation sitting down.

The Wisconsin-based firm, the self-described world's largest manufacturer of toilet seats, is suing a small Canadian company over what Bemis says is patent infringement and false advertising.

Among the issues: The descriptions by Centoco Plastics Ltd. of its model numbers 700 and 900, a pair of relatively inexpensive seats fashioned from molded wood and plastic.

Centoco, Bemis alleges in a suit filed recently in federal court, has claimed in its advertising "that Centoco toilet seats were superior or equal to Bemis toilet seats." Bemis says the Canadian firm hasn't backed that up, and that, in fact, Centoco's seats are inferior to Bemis products. Further, Bemis alleges, Centoco claims that the 700 and 900 - the former is round, the latter elongated - are made of molded wood when they actually "contain only 5 percent to 20 percent wood." All this has "deceived a substantial segment of consumers and potential customers," Bemis alleges.

Beyond that, Bemis claims Centoco has infringed on a Bemis patent relating to an injection molding process.

In its complaint, Bemis includes what it says is "a representative sample of Centoco's misleading advertising."

The ad, however, doesn't say Centoco seats are better than Bemis seats, or mention the company. The only claim to superiority is a headline that reads, "Our wood seats are highly durable and superior for high-traffic locations."

The ad describes the 700 and 900 as molded wood seats with a polypropylene shell. A cutaway diagram suggests that the seats are largely wood.

A Centoco product guide shows a U.S. list price of $8.68 for the 700 and $12.13 for its longer cousin. Those are relatively low prices for toilet seats, said Wayne Lautenbach, owner of Home Plumbing Supply in Milwaukee.

While Bemis contends Centoco is falsely portraying its products as being made of molded wood, Lautenbach said such seats generally aren't considered to be as good as their solid-plastic counterparts.

Wood seats have the advantage of allowing buyers to match hinges to other bathroom hardware, but plastic has no paint to wear off and tends to be more flexible, he said.

"Some people like the feel of it a little better," Lautenbach said. "It's a softer feel."