Bristol-Myers Squibb Company, Cross-Appellant v. mcneil-p.p.c., Inc., Cross-Appellee

This is an appeal from a preliminary injunction entered in the United States District Court for the Eastern District of New York, Spatt, J., in an action brought under section 43(a) of the Lanham Act, 15 U.S.C. § 1125(a), and various state unfair competition laws. The preliminary injunction prevents. the appellant, McNeil-P.P.C., Inc. (McNeil) from marketing its product, “Tylenol PM,” in the trade dress that it had been using prior to the injunction. Also before us is a cross-appeal by Bristol-Myers Squibb Company (Bristol) from the denial of preliminary injunctive relief preventing McNeil from using the term “PM” in connection with a combination analgesic/sleep aid.

As' in any case under section 43(a) of the Lanham Act, the ultimate question here is whether, because of the challenged markings, consumers are likely to be confused as to the origin or sponsorship of goods. Because we believe that the district court erred in finding that the “Tylenol PM” trade dress was likely to cause confusion among purchasers due to its similarity to Bristol’s “Excedrin PM” trade dress, we reverse the preliminary injunction. Because we agree with the district court’s denial of Bristol’s request preliminarily to enjoin McNeil’s use of the term “PM,” we affirm as to the cross-appeal.

Affirmed in part and reversed in part.

BACKGROUND

Bristol is a major pharmaceutical company that produces and markets “Excedrin,” *1037 a nationally known over-the-counter analgesic pain reliever. Since 1968 Bristol has manufactured and distributed “Exeedrin PM,” a product that combines an analgesic with a sleep aid.

Although there have been some alterations over the years, the packaging ■ of “Exeedrin PM” has remained fairly constant. That packaging consists of an outer carton with a solid deep blue background, white lettering for the name “Exeedrin PM,” which appears on a single line, with “Exeedrin” in lower case lettering except for the initial “E” and “PM,” which are in capital letters. In the' lower right portion of the face of the box is a depiction of two light blue tablets, each marked “PM.” In 1988, Bristol introduced a caplet form of “Exeedrin PM.” The trade dress for this caplet form is similar to that of the tablet form except that the background is a solid dark green and there is a depiction of two caplets each displaying the full name “Exeedrin PM.” On both packages the word “Exeedrin” occupies approximately one-third of the total face of the package.

McNeil is also a major pharmaceutical company. Among McNeil’s products is “Tylenol,” which, like “Exeedrin,” is a nationally famous over-the-counter analgesic. In 1991 McNeil introduced “Tylenol PM,” which, like “Exeedrin PM,” is a combination analgesic/sleep aid. Although there are slight differences in the composition of the two products, it is undisputed that those differences are not material and that the two products are functionally interchangeable. Like “Exeedrin PM,” “Tylenol PM” comes in two forms: tablet and caplet.

The packaging for the tablet form of “Tylenol PM” consists of a box with a green background that shifts from dark green at the top of the box to light green at the bottom and the name “Tylenol” in white capital letters with “PM” in yellow capital letters on the same line. In addition, the package depicts two tablets on the lower right face of the package, one of which is imprinted with the word “Tylenol” and the other of which is marked “PM.” The trade dress for the caplet form of “Tylenol PM” resembles that of the tablet form except that the background fades from dark to light blue rather than green and two caplets, each of which reads “Tylenol PM,” are depicted instead of the tablets. On both forms of the “Tylenol PM” trade dress, the word' “Tylenol” occupies approximately one-third of the total area of the face of the package.

Shortly after “Tylenol PM” was introduced, Bristol filed this action before Judge Spatt in the United States District Court for the Eastern District of New York, seeking relief ünder section 43(a) of the Lan-ham Act, 15 U.S.C. § 1125(a), and on various state law grounds. Bristol moved for a preliminary injunction to prevent McNeil from using the term “PM” in connection with a combination analgesic/sleep aid and to prevent McNeil from marketing an analgesic/sleep aid in the “Tylenol PM” packaging described above.

Judge Spatt referred the matter to Magistrate Judge Orenstein pursuant to 28 U.S.C. § 636(b)(1)(B). The magistrate judge heard evidence and examined exhibits and the results of discovery. The magistrate judge filed a report in the district court in which he made certain findings of fact and ultimately recommended that the preliminary injunction be denied. Both parties made timely objections to various portions of the magistrate judge’s report and the district court addressed the matter de novo pursuant to 28 U.S.C. § 636(b)(1).

The district court denied Bristol’s request for an injunction preventing McNeil from using the term “PM” in connection with an analgesic/sleep aid, finding that “PM” in this context did not qualify for protection under section 43(a) of the Lan-ham Act. The district court granted, however, Bristol’s request for an injunction with regard to the “Tylenol PM” trade dress because it found that Bristol, had demonstrated that the similarities between the two packages were likely to cause consumer confusion 786 F.Supp. 182. Both parties appealed and a panel of this Court stayed the preliminary injunction pending appeal.

*1038 DISCUSSION

I. PRELIMINARY INJUNCTION

In order to obtain a preliminary injunction, the moving party must demonstrate both (1) irreparable harm in the absence of the requested relief, and (2) either (a) a likelihood that it will succeed on the merits of the action, or (b) a sufficiently serious question going to the merits combined with a balance of hardships tipping decidedly in favor of the moving party. See Jackson Dairy v. H.P. Hood & Sons, 596 F.2d 70, 72 (2d Cir.1979) (per curiam). In the context of a Lanham Act claim both the likelihood of success on the merits and the potential for irreparable harm in the absence of preliminary relief may be demonstrated by a showing that a significant number of consumers are likely to be misled or confused as to the source of the products in question. Western Publishing Co. v. Rose Art Industries, 910 F.2d 57, 59 (2d Cir. 1990).

We have jurisdiction to review the grant or denial of a preliminary injunction pursuant to 28 U.S.C. § 1292(a)(1). We review a district court’s decision whether to issue a preliminary injunction only for an abuse of discretion. Doran v. Salem Inn, 422 U.S. 922, 931-32, 95 S.Ct. 2561, 2567-68, 45 L.Ed.2d 648 (1975). “Applying legal standards incorrectly or relying upon clearly erroneous findings of fact may constitute an abuse of discretion.” Haitian Centers Council v. McNary, 969 F.2d 1326, 1338 (2d Cir.1992) (citation omitted). We are not, however, limited to “reversing only when the lower court’s action exceeds any reasonable bounds and to rubber-stamping with the imprimatur of an affirmance when it does not.” Coca-Cola Co. v. Tropicana Products, 690 F.2d 312, 315 (2d Cir.1982) (citation omitted). Although our scope of .review is limited, if we are left with “ ‘the definite and firm conviction that a mistake has been committed’ ” we will reverse the grant or denial of a preliminary injunction. See Standard & Poor’s Corp. v. Commodity Exchange, 683 F.2d 704, 708 (2d Cir.1982) (quoting United States v. United States Gypsum Co., 333 U.S. 364, 395, 68 S.Ct. 525, 542, 92 L.Ed. 746 (1948)). With these principles in mind, we turn to the parties’ specific claims.

II. THE LANHAM ACT CLAIMS

Neither the “PM” designator nor the “Excedrin PM” trade dress is a registered trademark. Bristol, therefore, relies on that part of the Lanham Act that addresses unregistered marks. Section 43(a) of the Lanham Act prohibits any person from using

in connection with any goods ... or any container for goods, ... any word, term, name, symbol, or device, or any combination thereof ... which ... is likely to cause confusion, or to cause mistake, or to deceive ... as to the origin, sponsorship, or approval of his or her goods ... by another person.

15 U.S.C. § 1125(a). 1 “[I]t is common ground that § 43(a) protects qualifying unregistered trademarks and that the general principles qualifying a mark for registration under § 2 of the Lanham Act are for the most part applicable in determining whether an unregistered mark is entitled to protection under § 43(a).” Two Pesos, Inc. v. Taco Cabana, Inc., — U.S.-,-, 112 S.Ct. 2753, 2757, 120 L.Ed.2d 615 (1992) (citations omitted). As the words of the statute indicate, the central inquiry is whether the use of a marking is likely to cause consumer confusion.

Bristol makes two related claims under section 43(a). First, Bristol claims that the use by McNeil of the term “PM” in connection with its combination analgesic/sleep aid is likely to cause confusion as to the source, sponsorship or approval of “Tylenol *1039 PM.” Second, Bristol claims that the overall look of the “Tylenol PM” packaging, its trade dress, is so similar to the trade dress of Bristol’s “Excedrin PM” that consumers will confuse the two.

Before we will address whether an allegedly infringing mark is likely to cause consumer confusion, the plaintiff must show that its trademark or trade dress is of the type that deserves protection under section 43(a). See Thompson Medical Co. v. Pfizer, Inc., 753 F.2d 208, 213 (2d Cir.1985). The plaintiff then must demonstrate that the use by the defendant of a mark or dress is likely to cause consumer confusion because of the similarity between the defendant’s mark or dress and the mark or dress of the plaintiff. See id.

A. Trademark Infringement: The “PM” Designator

To facilitate our analysis, we will deal first with the cross-appeal. Bristol appeals from the district court’s refusal to grant preliminary injunctive relief preventing McNeil from using the term “PM” appended to its “Tylenol” trade name to designate its combination analgesic/sleep aid. Under the terms of the preliminary injunction, McNeil remains free to market “Tylenol PM” in a trade dress that does not resemble the “Excedrin PM” trade dress. The district court agreed with the magistrate judge that the term “PM” as used by Bristol did not warrant protection under section 43(a).

In making the preliminary inquiry into whether a particular mark is eligible for protection under section 43(a), we have established several categories into which we classify various marks. “Arrayed in an ascending order which roughly reflects their eligibility to trademark status and the degree of protection accorded, these classes are (1) generic, (2) descriptive, (3) suggestive, and (4) arbitrary or fanciful.” Abercrombie & Fitch Co. v. Hunting World, 537 F.2d 4, 9 (2d Cir.1976). Suggestive, arbitrary and fanciful marks, “because their intrinsic nature serves to identify a particular source of a product, are deemed inherently distinctive and are entitled to protection.” Two Pesos, — U.S. -, 112 S.Ct. at 2757. Generic marks are never entitled to protection, while a descriptive mark is eligible for protection “if it ‘has become distinctive of the [producer’s] goods in commerce.’ This acquired distinctiveness is generally called ‘secondary meaning.’ ” Id. — U.S. at-, 112 S.Ct. at 2757 (citations omitted).

Although we have not expressly articulated the standard of review appropriately applied to a district court’s classification of a mark, other courts of appeals have found that classification to be a factual question, review of which is limited to whether the district court was clearly erroneous in its determination. See, e.g., Ford Motor Co. v. Summit Motor Products, 930 F.2d 277, 292 n. 18 (3d Cir.) (“The characterization of a mark is a factual issue.”) (citations omitted), cert. denied, — U.S. -, 112 S.Ct. 373, 116 L.Ed.2d 324 (1991); G. Heileman Brewing Co. v. AnheuserBusch, 873 F.2d 985, 992 (7th Cir.1989) (“[T]he district court’s classification of a term on the trademark spectrum is a factual determination subject to the ‘clearly erroneous’ standard of review.”); Wiley v. American Greetings Corp., 762 F.2d 139, 141 (1st Cir.1985) (“Whether a design is ‘inherently distinctive,’ i.e., whether it is arbitrary or merely descriptive, is ordinarily a question of fact.”) (citation omitted); Anheuser-Busch v. Stroh Brewery Co., 750 F.2d 631, 635 (8th Cir.1984) (“[T]he categorization of a term for which trademark protection is claimed is considered to be a factual issue and thus is to be reviewed under the clearly erroneous standard of Fed.R.Civ.P. 52(a).”) (citations omitted); Soweco, Inc. v. Shell Oil Co., 617 F.2d 1178, 1183 n. 12 (5th Cir.1980) (“Any given term’s correct categorization is a factual issue.”) (citations omitted), cert. denied, 450 U.S. 981 (1981); cf. In re Northland Aluminum Products, 777 F.2d 1556, 1559 (Fed.Cir.1985) (“Whether a term is a common descriptive name is a question of fact” in context of trademark registration.) (citation omitted). We agree with these courts that the initial classification of a mark to determine its eligibility for protec *1040 tion is a question of fact left to the determination of the district court. We will substitute our own judgment on the matter for that of the district court only if the district court’s determination is clearly erroneous. Fed.R.Civ.P. 52(a).

The district court classified the “PM” mark as descriptive. Bristol argues that the mark is suggestive. Neither party claims that the mark is generic, arbitrary or fanciful. The question in this case, therefore, is whether “PM,” when affixed to an analgesic trade name, is descriptive or suggestive of the product, a combination analgesic/sleep aid.

A descriptive mark is one that “ ‘forthwith conveys an immediate idea of the ingredients, qualities or characteristics of the goods.’ ” Abercrombie & Fitch, 537 F.2d at 11 (citation omitted). “[A] term can be descriptive in two ways. It can literally describe the product, or it can describe the purpose or utility of the product.” 20th Century Wear v. Sanmark-Stardust, 747 F.2d 81, 88 (2d Cir.1981), cert. denied, 470 U.S. 1052, 105 S.Ct. 1755, 84 L.Ed.2d 818 (1985). A term is suggestive “ ‘if it requires imagination, thought and perception to reach a conclusion as to the nature of goods.’ ” Abercrombie & Fitch, 537 F.2d at 11 (citation omitted).

Although the line between descriptive and suggestive may be difficult to discern, see id. at 10-11, the consequence of the classification is important. A descriptive term is subject to protection under section 43(a) only if the proponent of protection demonstrates that, in addition to the ordinary common meaning of the word or words, the term has acquired a secondary meaning in its particular market — that the consuming public primarily associates the term with a particular source. See Centaur Communications, Ltd. v. A/S/M Communications, 830 F.2d 1217, 1221 (2d Cir.1987); Thompson Medical, 753 F.2d at 212-13. The public presumably will not be confused by a descriptive term, but if the proponent of protection can show that the descriptive term is primarily associated with a single producer, a sufficient question is raised to justify further inquiry into the likelihood of confusion. In contrast, if its mark is suggestive a plaintiff need not prove such secondary meaning in order to qualify for trademark protection. Id. at 213.

In this case, the “PM” acts as a modifier to the analgesic brand name. Both “Tylenol” and “Excedrin” are well known brand names for analgesics; the “PM” modifies each to show that they are a particular type of analgesic. “PM,” usually abbreviated “p.m.” or “P.M.” (for “post meri-diem”), is a common term that refers to the period of time between noon and midnight. It is often associated with the time when most people go to sleep.

As used here, “PM” does not literally describe the presence of a sleep aid in the product. The “PM” refers to the purpose or utility of the product — it is an analgesic that should be used at night. The issue, therefore, is whether the connection between “PM” and a nighttime sleep aid is direct enough that the term may be categorized as descriptive or whether the connection is more indirect, requiring categorization as suggestive.

Bristol argues that “PM” is suggestive because a consumer must engage in a mul-ti-step analysis before coming to the conclusion that it denotes the presence of a sleep aid in the analgesic. Bristol asserts that the consumer first must eliminate possible alternate meanings for “PM” — e.g., “Pre-Menstrual” or “Pain Medication”— before arriving at “Post Meridiem.” Next, Bristol argues, the consumer must make a leap from all the post meridiem hours to those at night, and a further intellectual leap from nighttime to sleeping.

The magistrate judge found that several other over-the-counter products are designated as nighttime products by the use of some close variant of “PM.” The magistrate judge held in that context that “[t]he direct connotation of ‘PM’ is nighttime. There is no ‘multi-stage reasoning process’ that a consumer must indulge in to associate the term ‘PM’ with a nighttime product.”

*1041 We cannot say that the district court’s adoption of this finding was clearly erroneous. The focus in categorizing a mark is on how the words are used in context rather than their meaning in the abstract. See Abercrombie & Fitch, 537 F.2d at 12. One of the leading commentators has offered the following example to demonstrate the context-dependent nature of the classification: “[T]he word ‘apple’ would be arbitrary when used on personal computers, suggestive when used in ‘Apple-A-Day’ on vitamin tablets, descriptive when used in ‘Tomapple’ for combination tomato-apple juice and generic when used on apples.” 1 J.T. McCarthy, Trademarks and Unfair Competition § 11:22, at 498-99 (2d ed. 1984). There was sufficient evidence before the magistrate judge to support the finding that several nighttime products were sold using some variant of “PM.” Given that context, the conclusion that “PM” describes rather than suggests a nighttime product was not clearly erroneous. Once the consumer arrives at an awareness that the product is useful at nighttime, the “purpose or utility” of the product has been conveyed, even though the consumer is not aware of why the product is useful at night. See Thompson Medical, 753 F.2d at 216 & n. 15 (“Sportscreme” descriptive of cream useful in sports even though inadequately descriptive as to significance of product). Therefore, the consumer need not conclude that the analgesic contains a sleep aid.

Given the deferential standard of review, and the fact that this matter is before us at the preliminary injunction stage, we will not disturb the district court’s finding that “PM” is descriptive.

Because “PM” is a descriptive term it is not entitled to trademark protection unless Bristol demonstrates secondary meaning. The district court found that Bristol had not established that the “PM” designator had acquired secondary meaning. We agree with the district court.

“To establish secondary meaning, a manufacturer must show that, in the minds of the public, the primary significance of a product feature or term is to identify the source of the product rather than the product itself.” Inwood Laboratories v. Ives Laboratories, 456 U.S. 844, 851 n. 11, 102 S.Ct. 2182, 2187 n. 11, 72 L.Ed.2d 606 (1982) (citation omitted). Secondary meaning is an essentially factual determination, proof of which “ ‘entails vigorous evidentiary requirements.’ ” Thompson Medical, 753 F.2d at 217 (citation omitted); see Coach Leatherware v. AnnTaylor, Inc., 933 F.2d 162, 169 (2d Cir.1991). We will reverse the district court’s determination that a term has not acquired secondary meaning only if that determination is clearly erroneous. See Murphy v. Provident Mut. Life Ins., 923 F.2d 923, 928 (2d Cir.1990), cert. denied, — U.S. -, 112 S.Ct. 65, 116 L.Ed.2d 40 (1991); 815 Tonawanda Street Corp. v. Fay’s Drug Co., 842 F.2d 643, 647 (2d Cir.1988).

Among the factors that we have found relevant to this inquiry in the past are advertising expenditures, consumer studies, sales success, unsolicited media coverage, attempts to plagiarize and length and exclusivity of use. Thompson Medical, 753 F.2d at 217. There are undoubtedly other types of evidence that would also be relevant to a claim of secondary meaning. The fundamental question, however, is whether “ ‘the primary significance of the term in the minds of the consuming public is not the product but the producer.’ ” Centaur Communications, 830 F.2d at 1221 (citations omitted).

“The existence of secondary meaning is a question of fact with the burden of proof on the party claiming exclusive rights in the designation.” PaperCutter, Inc. v. Fay’s Drug Co., 900 F.2d 558, 564 (2d Cir.1990) (citation omitted). The district court found that Bristol had not presented sufficient evidence that consumers recognized the source of “Excedrin PM” by the “PM” designator and that there was no evidence that Bristol had ever marketed the product as “PM.”

Bristol suggests two grounds in support of its contention that the district court’s finding that the “PM” mark had not acquired secondary meaning was clearly *1042 erroneous. First, Bristol argues that McNeil’s intentional copying of its mark is indicative of secondary meaning. Although imitative intent can help support a finding of secondary meaning, see Centaur Communications, 830 F.2d at 1224, it does not necessarily mandate one, see American Footwear Corp. v. General Footwear Co., 609 F.2d 655, 663 (2d Cir.1979) (“[N]o single factor is determinative.”), cert. denied, 445 U.S. 951, 100 S.Ct. 1601, 63 L.Ed.2d 787 (1980). Therefore, we believe that, even assuming McNeil’s imitative intent, the district court was not bound to find that the “PM” designator had acquired secondary meaning.

Second, Bristol argues that the fact that each “Excedrin PM” tablet is imprinted with “PM” shows that the consuming public must associate “PM” with Bristol. However, “[although the mark owner strives to create a secondary meaning for its product, it is the consuming public which, in effect, determines whether that effort has succeeded.” Centaur Communications, 830 F.2d at 1221 (citations omitted). The mere fact that Bristol places the name “PM” on its tablets does not persuade us that the consuming public associates that term with Bristol. Moreover, on the larger caplet version of the product, Bristol placed the entire “Excedrin PM” mark.

The district court was not clearly erroneous in classifying “PM” as a descriptive term in these circumstances. Because “PM” had not become primarily associated with a single producer in these circumstances, “PM” as used by Bristol is not by itself subject to protection under the Lan-ham Act. The district court therefore properly declined to enjoin McNeil from using the “PM” designator in connection with its combination analgesic/sleep aid.

B. Trade Dress Infringement

McNeil appeals from the entry of a preliminary injunction preventing it from marketing “Tylenol PM” in the packaging that the district court found to have infringed on Bristol's trade dress. The “trade dress” of a product “ ‘involves the total image of a product and may include features such as size, shape, color or color combinations, texture, [or] graphics.’ ” LeSportsac, Inc. v. K mart Corp., 754 F.2d 71, 75 (2d Cir.1985) (citation omitted). In examining trade dress the focus is on the entire look of the product or packaging. Individual aspects of a trade dress may be eligible for trademark protection in their own right, but in an action for trade dress infringement each aspect should be viewed in relation to the entire trade dress. The inquiry is whether the trade dress of a “junior user” — one who has adopted its mark or dress later than the “senior user” — is likely to cause consumer confusion as to the source of the product. As in the trademark arena, we must first determine whether a particular trade dress is eligible for protection under the Lanham Act.

The district court proceeded on the assumption, formerly the law in this Circuit, that, unlike trademarks, a trade dress was always ineligible for protection under section 43(a) in the absence of proof of secondary meaning. See, e.g., LeSportsac, 754 F.2d at 75. The Supreme Court, however, recently rejected this distinction between trademarks and trade dress. Two Pesos, — U.S. at-, 112 S.Ct. at 2760 (“We see no basis for requiring secondary meaning for inherently distinctive trade dress protection under § 43(a) but not for other distinctive words, symbols, or devices capable of identifying a producer’s product.”).

The district court made no finding as to whether the “Excedrin PM” trade dress was “inherently distinctive.” However, if the district court was correct in determining that the trade dress had acquired secondary meaning, that dress is eligible for protection under section 43(a).

1, Secondary Meaning

The secondary meaning inquiry is the same for trade dress as it is for a trademark. Bristol must show that the primary significance of its “Excedrin PM” trade dress is to identify the source of the product rather than the product itself. See Inwood Laboratories, 456 U.S. at 850-51 n. *1043 11, 102 S.Ct. at 2187 n. 11. The question whether a mark or dress has acquired secondary meaning is a factual one that we will not reverse unless it is clearly erroneous. See Murphy, 923 F.2d at 928; 815 Tonawanda Street Corp., 842 F.2d at 647. The district court properly examined the Thompson Medical factors and concluded that Bristol’s “Excedrin PM” trade dress had acquired secondary meaning. See Thompson Medical, 753 F.2d at 217.

The district court found that Bristol’s advertising expenditures in connection with “Excedrin PM” and its sales success weighed in favor of a finding of secondary meaning for the trade dress. It further held that consumer survey evidence introduced by Bristol, “though problematic in terms of some of its methodology,” supported Bristol’s claim of secondary meaning. The district court finally found that McNeil intentionally copied the “Excedrin PM” trade dress.

Given the deferential standard of review, we cannot say that the district court clearly erred in determining that the overall trade dress of “Excedrin PM” had acquired secondary meaning. This conclusion is strengthened by the well known trade name “Excedrin” prominently displayed on the “Excedrin PM” box as an integral part of the whole trade dress. That name strongly supports the district court’s determination that consumers associate the trade dress, taken as a whole, with a particular producer.

2. Likelihood of Confusion

Having determined that the district court did not err in finding that the “Excedrin PM” trade dress is eligible for protection under section 43(a), we turn to the central question in this case: Whether McNeil’s use of the “Tylenol PM” trade dress is likely to cause confusion as to the “origin, sponsorship, or approval” of “Tylenol PM” with “Excedrin PM.” See 15 U.S.C. § 1125(a)(1).

Whether the public is likely to confuse two products is a question that is not easily answered. Our cases, however, have established an analytical framework designed to add structure to this nebulous inquiry and to guide judicial decisions toward some degree of predictability and uniformity.

In Polaroid Corp. v. Polarad Electronics Corp., 287 F.2d 492 (2d Cir.), cert. denied, 368 U.S. 820, 7 L.Ed.2d 25 (1961), we examined similar marks used for dissimilar products. We set forth the following nonexclusive list of factors relevant to success on a Lanham Act claim:

the strength of [the prior owner’s] mark, the degree of similarity between the two marks, the proximity of the products, the likelihood that1 the prior owner will bridge the gap [between the two products], actual confusion, and the reciprocal of defendant’s good faith in adopting its own mark, the quality of defendant’s product, and the sophistication of the buyers.

Id. at 495. We have subsequently held that these factors are appropriately considered when examining the likelihood of confusion between two competing products. See, e.g., Thompson Medical, 753 F.2d at 213-14.

The standard of appellate review of a district court’s conclusion regarding the likelihood of confusion between two products has split the courts of appeals. See Euroquilt, Inc. v. Scandia Down Corp., 475 U.S. 1147, 106 S.Ct. 1801, 90 L.Ed.2d 346 (1986) (White, ,/., dissenting from the denial of certiorari to resolve whether the determination of likelihood of confusion under section 43(a) is subject to de novo review as a conclusion of law or “clearly erroneous” review as a question of fact). In this Circuit, a district court’s determination of the individual Polaroid factors are subject to review as findings of fact, subject to reversal only if clearly erroneous, while the ultimate balancing of all the Polaroid factors to determine the likelihood of confusion in any given case is done de novo by this Court. See Murphy, 923 F.2d at 928; Western Publishing, 910 F.2d at 61.

Some earlier cases in this Circuit have held that to the extent that the Polaroid factors rest on a comparison of the marks *1044 themselves we are in as good a position to evaluate them as the district court and thus will evaluate those factors de novo. See, e.g., McGregor-Doniger v. Drizzle, 599 F.2d 1126, 1133 (2d Cir.1979). However, Rule 52(a) of the Federal Rules of Civil Procedure was amended in 1985 to require that “[findings of fact, whether based on oral or documentary evidence, ... not be set aside unless clearly erroneous.” Fed. R.Civ.P. 52(a). The Notes of the Advisory Committee on Rules accompanying that amendment emphasize that even where the appellate court is in as good a position as the trial court to make a given factual determination, the factfinding function should be left to the district courts because of “the public interest in ... stability and judicial economy.” Notes of Advisory Committee on Rules, 1985 Amendment. Thus, each of the Polaroid factors should be reviewed under Rule 52(a). Cf. Johnson & Johnson v. GAC International, 862 F.2d 975, 979 (2d Cir.1988) (finding of falsity in advertisement, formerly reviewed de novo, reviewed under amended Rule 52).

The only case that applies a de novo review to any Polaroid factor since the amendment to Rule 52(a) is Centaur Communications, 830 F.2d at 1226 (“Unlike the other factors, this finding [with regard to similarity of the marks] is reviewed de novo because an appellate court is in as good a position to evaluate this factor as is a trial court.”) (citations omitted). In that case, the Court did not examine the amendment to Rule 52, and its statement that we review similarity of the marks de novo was not necessary to its holding. Therefore, we do not find that statement controlling.

Despite the existence and importance of the Polaroid factors, we must remember that they are merely tools “designed to help grapple with the ‘vexing’ problem of resolving the likelihood of confusion issue,” and that “the ultimate conclusion as to whether a likelihood of confusion exists' is not to be determined in accordance with some rigid formula.” Lois Sportswear v. Levi Strauss & Co.,