No amount of change is guaranteed to keep you clear of copyright infringement. The common belief that altering 10%, 20%, or 30% of an artwork makes a copy legally safe is a myth. United States copyright law contains no percentage rule and no checklist. When you ask how much you have to change artwork to avoid copyright infringement, the honest answer is that courts do not measure change at all. They measure what you kept, and whether your use serves a genuinely different purpose from the original.
That reframing matters, because artists who rely on a percentage can still lose. Below is how the law actually looks at the question, and what to do instead.
What Copyright Actually Protects
Copyright protects the specific expression of an idea, not the idea itself. No one owns the concept of a city skyline at night. What is protected is a particular painting of that skyline: its composition, color palette, brushwork, and perspective, fixed in a tangible form. Protection attaches automatically the moment an original work is fixed on canvas, in a digital file, or in a sketchbook.
Styles and techniques are free for anyone to use. Cubism, impasto, pointillism, and standard genre elements belong to no one. Painting in another artist’s style is legal. Reproducing their specific protected expression is where the trouble starts. The doctrine of scènes à faire reinforces this: elements that are standard to a genre, like cowboys, dusty streets, and saloons in a Western scene, are not protectable on their own.
Older work eventually falls out of protection entirely. As of January 1, 2026, works published with a copyright notice in 1930 or earlier are in the public domain, and can be used, copied, or adapted freely.
Why Changing the Artwork Doesn’t Fix the Problem
The percentage myth collapses on a single point of federal law: the copyright holder has the exclusive right to prepare derivative works based on the original. A derivative work is any new work built on a preexisting one, including reproductions, adaptations, and transformations. Making one without permission is itself infringement, no matter how much original material you add.
The Copyright Office has stated this directly: “The unauthorized adaptation of a work may constitute copyright infringement,” and copyright protection “will not extend to any part of the work in which such material has been used unlawfully.” If you take someone’s painting, change 30% of it, and release it as yours, you have created an unauthorized derivative work. Your new 30% does not launder the 70% you copied. A court can still find infringement based on what remains.
This is why “how much did I change” is the wrong question. The law does not ask how much you changed. It asks how much of the protected expression is still there.
The Test Courts Actually Use
Infringement claims are decided under a “substantial similarity” standard. A plaintiff generally has to show two things: that the accused artist had access to the original, and that the new work is substantially similar to the original’s protected expression.
Access means a reasonable opportunity to see or copy the work. Courts recognize access through a chain of connections (a shared gallery or publisher), wide public availability of the original, or a similarity so striking that independent creation is implausible.
Similarity is usually evaluated in two parts. The extrinsic test is an objective comparison of specific expressive elements: composition, color choices, arrangement of subjects, artistic details. The intrinsic test is subjective, asking whether an ordinary reasonable viewer would find the works substantially similar in their total concept and feel.
For visual art, the intrinsic test often does the heavy lifting. It asks whether an average viewer, without art training, would recognize one work as a copy of the other. Small differences in size, medium, or palette will not save an infringing piece if the overall aesthetic impression is the same. Two sculptures of a coiled serpent would not be compared just as “both are snakes.” A court would look at posture, texture, the shape of the head, the mood. If the second evokes the same unique artistic vision as the first, similarity can be found even where surface details differ.
Notice what is missing from this test: any measurement of percentage changed.
When a Changed Work Can Still Be Lawful: Fair Use
Fair use is the doctrine most people are gesturing at when they ask how much to change. It permits limited use of copyrighted material without permission. But it is a defense you raise after being sued, not a permission slip you get in advance, and it is decided on four factors weighed together:
- Purpose and character of the use. Is the new work transformative, adding new meaning, message, or purpose? Is it commercial? Parody, criticism, commentary, and education weigh in favor. Selling prints that compete with the original weighs against.
- Nature of the copyrighted work. Highly creative works like paintings and illustrations get stronger protection than factual works.
- Amount and substantiality of what was used. Taking a small but iconic portion, the “heart” of the work, can weigh more heavily against fair use than borrowing a larger but unremarkable portion.
- Effect on the market. If your work competes with the original or undercuts its licensing value, this factor cuts hard against fair use.
No factor is decisive. Courts weigh them together, and the analysis is highly fact-specific.
The Warhol Decision Narrowed the Path
The Supreme Court’s 2023 decision in Andy Warhol Foundation for the Visual Arts, Inc. v. Goldsmith reshaped how the first factor is analyzed. The case involved Warhol’s silkscreen print of the musician Prince, based on a photograph by Lynn Goldsmith. The Warhol Foundation argued the print was transformative because it carried a different artistic message. The Court disagreed, 7–2.
The majority held that when a new work is used for a commercial purpose substantially similar to the original’s, simply adding new expression or meaning is not enough to make it transformative. Both Goldsmith’s photograph and Warhol’s print served the same function: commercial portraits licensed to magazines. Because they competed in the same market for the same purpose, the first factor weighed against the Foundation.
The takeaway for artists is direct. Before Warhol, many believed a new artistic perspective was enough to claim fair use. The Court made clear that purpose matters as much as message. If your version serves the same commercial function as the original, a new interpretation alone will probably not protect you, no matter how much you altered the surface.
What It Costs to Guess Wrong
The financial exposure is one reason the percentage gamble is a bad bet.
A copyright owner can recover either actual damages plus the infringer’s profits, or statutory damages. Actual damages compensate proven losses, and profits are calculated from gross revenue. Once the owner proves gross revenue, the burden shifts to the infringer to prove which expenses are deductible and which profits came from other factors.
Statutory damages are available as an alternative. For a standard infringement, a court can award between $750 and $30,000 per work infringed. If the infringement was willful, the ceiling jumps to $150,000 per work. If the infringer genuinely did not know and had no reason to believe the use was infringing, the minimum can drop to $200.
Courts can also award attorney’s fees to the prevailing party and issue injunctions blocking further use of the work. Copyright litigation is expensive, and the possibility of paying both sides’ fees makes even a modest claim financially serious.
Practical Steps That Replace the Percentage Question
Instead of asking how much to change, ask what new meaning, context, or purpose your work provides, and how much of the original’s specific expression is still visible in yours. That is how a court will look at it.
- Work from multiple references. Combining elements from several sources with your own creative choices produces work that is genuinely original rather than a modified copy of one piece.
- Document your process. Sketches, drafts, mood boards, and notes about your intent serve as evidence of independent creation if your work is ever questioned.
- Separate style from expression. Drawing on another artist’s technique or aesthetic is legal. Reproducing their specific composition, color arrangement, or distinctive visual elements is not.
- Think hard about purpose. After Warhol, commercial use that serves the same market as the original is a real risk factor. Work that competes for the same audience or licensing opportunities is much harder to defend as fair use.
- License when in doubt. A license is the only way to use another artist’s protected expression with no risk of infringement. For anyone building on an existing work, permission eliminates the uncertainty of a fair use defense that may not hold.
Copyright law does not reward cleverness about how much you altered. It asks whether what you kept was someone else’s protected expression, and whether your use serves a genuinely different purpose. No percentage answers either question.