A patent of design protects how something looks. Nothing else.
Not how it works, not what it does, not the idea behind it. Those are utility patent questions, and the two categories do not overlap.
The drawings are the claim. A design patent has a single claim phrased as the ornamental design as shown, which means every line in every figure is doing legal work.
And it requires no maintenance fees, which is why almost all design patents run their full fifteen years while 58.6% of utility patents do not.
Design against utility
| Design patent | Utility patent | |
|---|---|---|
| Protects | Ornamental appearance | Function |
| The claim is | The drawings | Written claims |
| Number of claims | One | Often 20 |
| Term | 15 years from grant | 20 years from filing |
| Maintenance fees | None | Three, up to $14,470 |
| Infringement test | Ordinary observer | Every element present |
| Number prefix | D | None |
| Reaches full term | Almost always | 41.4% |
Two structural differences drive everything else. Term running from grant, and no fees.
The single claim
The ornamental design for a beverage container, as shown and described.
That is the whole claim. Everything about scope is decided by the figures.
| Line type | Meaning |
|---|---|
| Solid lines | Claimed — part of the protected design |
| Broken lines | Unclaimed — environment, context, disclaimed features |
| Oblique shading | Transparent surfaces |
| Surface shading | Contour and three-dimensional form |
Broken lines broaden the patent. Converting a feature from solid to broken disclaims it, which means the design is protected regardless of what that feature looks like.
This is claim drafting, not illustration. A line-type error changes what you own. See patent drawing.
Worked example: line types changing scope
A chair design, three versions of the same application.
| Version | Solid lines | Protects |
|---|---|---|
| A | Entire chair | Only chairs looking like this entirely |
| B | Backrest only; legs and seat broken | This backrest on any chair |
| C | Leg profile only; rest broken | This leg on any chair |
| Version A | Version B | Version C | |
|---|---|---|---|
| Breadth | Narrowest | Broader | Broader |
| Competitor changes the legs | Avoids it | Still infringes | Avoids |
| Competitor changes the backrest | Avoids | Avoids | Still infringes |
Version A is the common mistake. Claiming the whole article means any visible change may avoid it.
Multiple applications on the same product are normal, each claiming a different portion, which is how designers build coverage that is hard to work around.
The ordinary observer test
| Element | Detail |
|---|---|
| The observer | An ordinary observer, giving ordinary attention |
| Familiar with the prior art | Not a naive viewer |
| Question | Would they be deceived into thinking one is the other? |
| Comparison | Overall visual impression |
| Not | Element-by-element, as with utility claims |
Prior art matters to the comparison. In a crowded field, small differences carry more weight because an observer familiar with the field notices them.
In a sparse field, the same differences may not save an accused design.
This is a fundamentally different test from utility infringement, where every claim element must be present and overall similarity is irrelevant.
Functionality is the main limit
| Situation | Protectable? |
|---|---|
| Shape chosen for appearance | Yes |
| Shape dictated solely by function | No |
| Shape with functional and ornamental aspects | Ornamental aspects, yes |
| Alternative designs exist that work equally well | Supports ornamentality |
| Only one shape works | Suggests functionality |
The existence of alternatives is the practical test. If competitors achieve the same function with visibly different shapes, the shape you chose was a design choice.
Functionality is the main invalidity risk for design patents, and it is where challenges concentrate.
Prior art for designs
| Reference type | Counts? |
|---|---|
| Earlier design patents | Yes |
| Registered designs abroad | Yes |
| Products on sale | Yes, whether registered or not |
| Catalogues and advertisements | Yes |
| Utility patent drawings | Yes, if they show the appearance |
| Your own disclosure, within a year, US | Grace period |
Anticipation asks whether an earlier design is substantially the same to an ordinary observer, which is the same visual comparison used for infringement.
Obviousness works differently from utility patents. It starts from a primary reference with basically the same overall appearance, which can then be modified by secondary references.
Products on sale matter as much as registered designs, and no design register contains them.
Damages under section 289
| Remedy | Available |
|---|---|
| Reasonable royalty | Yes |
| Lost profits | Yes |
| Total profit on the article of manufacture | §289 — design patents only |
| Injunctions | On the equitable factors |
Section 289 has no utility patent equivalent. An infringer's entire profit on the article can be awarded, without apportionment to the design's contribution.
What counts as the article of manufacture was addressed in Samsung v. Apple — it may be the whole product or a component, depending on the facts, which materially affects the size of the award.
Marking still limits pre-notice damages, exactly as with utility patents. See patent marking.
No fees means no attrition
| Ipiry Patent Survival Curve v1.0 | Utility patents |
|---|---|
| Survive the 3.5-year fee (2022 cohort) | 85.8% |
| Survive the 7.5-year fee (2018 cohort) | 64.6% |
| Reach full term (2014 cohort) | 41.4% |
| Abandoned before full term | 58.6% |
| Lost at the third fee | 23.2 points |
Computed from 27,273,654 USPTO maintenance fee records covering 8,262,336 US utility patents — see the patent survival curve.
Every one of those abandonments happened at a fee window. Design patents have none, so those figures do not apply to them at all.
Nothing an owner forgets to do ends a design patent. That is the practical difference day to day.
What can still end one
| Route | Effect |
|---|---|
| Invalidation for functionality | The main risk |
| Invalidation over prior designs | Anticipation or obviousness |
| Terminal disclaimer | Term capped to an earlier related patent |
| Abandonment before grant | No patent at all |
| Term expiry | Permanent |
Terminal disclaimers appear where several related designs are filed. A disclaimer overcoming a double-patenting rejection ties the later patent's expiry to the earlier one.
Design patents and utility patents together
| Aspect of a product | Protection | Clock |
|---|---|---|
| The mechanism | Utility patent | 20 yrs from filing, three fees |
| The appearance | Design patent | 15 yrs from grant, no fees |
| The name | Trademark | Indefinite with renewal |
| The manuals and software | Copyright | Long |
| The manufacturing process | Trade secret | While secret |
The design patent frequently outlives the utility patent in practice, because the utility patent may be abandoned at a fee window while the design patent simply continues.
They are complementary, not alternatives. See types of patents.
Recognising infringement
| Signal | Weight |
|---|---|
| Overall visual impression matches | Decisive |
| Minor differences in a crowded field | May avoid |
| Minor differences in a sparse field | May not save it |
| Different function, same look | Still infringes |
| Same function, different look | Does not |
Function is irrelevant to design infringement. A competitor whose product works completely differently but looks the same still infringes.
Against trade dress
| Design patent | Trade dress | |
|---|---|---|
| Duration | 15 years, fixed | Indefinite |
| Requires | Registration | Secondary meaning through use |
| Available from | Grant | After years of use |
| Functionality bar | Applies | Applies |
| Cost | One-off | Ongoing enforcement |
Filing the design patent buys the fifteen years during which trade dress is being established. That is the practical sequencing for a distinctive product shape.
Enforcement in practice
| Step | Detail |
|---|---|
| 1. Verify your patent is in force | Design patents do not lapse, but confirm |
| 2. Compare overall visual impression | Ordinary observer, aware of prior art |
| 3. Assess the prior art field | Crowded fields need closer similarity |
| 4. Check functionality exposure | The likely defence |
| 5. Consider §289 total profit | Distinctive remedy |
| 6. Marking status | Limits pre-notice damages if omitted |
Functionality is the defence you should expect, so assess it honestly before asserting. If no visibly different alternative achieves the same function, the design may be vulnerable.
Prior art context changes the comparison in both directions, which is why a search matters before enforcement as well as before filing.
Where design patents earn their term
| Product type | Useful protection |
|---|---|
| Fashion and consumer goods | Often short — the look dates |
| Furniture and housewares | Long |
| Automotive replacement parts | Long — serviced for decades |
| Consumer electronics | Short — form factors change |
| Packaging and containers | Long — a shape persists |
| Medical device housings | Medium to long |
Replacement parts are where the full fifteen years pay out. A design patent on a body panel or a filter housing stays commercially live as long as the machine is serviced.
For short-cycle products, the absence of fees is what matters. A design patent on a discontinued product costs nothing to keep, which is not true of a utility patent.
Multiple embodiments in one application
| Permitted | Where they are patentably indistinct |
| Restriction requirement | If the examiner considers them distinct |
| Result of restriction | Elect one; others go to divisionals |
| Common approach | Separate applications from the start |
Filing separate applications avoids the restriction problem and produces the layered coverage that makes a design hard to work around.
A divisional keeps non-elected embodiments alive, but only if filed before the parent issues.
Getting one
| Design application | Utility application | |
|---|---|---|
| Claims | One | Often 20 |
| Specification | Very short | Extensive |
| Drawings | The substance | Supporting |
| Views | 6 orthographic plus perspective | As needed |
| Rejection grounds | Prior designs, functionality, indefiniteness | §101, §102, §103, §112 |
| Cost to obtain | Substantially lower | $8,000–$20,000 |
Inconsistency between views draws objections. The figures must describe one coherent three-dimensional object.
Informal drawings can be filed and replaced with formal ones later, which is common practice.
Filing timing
| Point | Detail |
|---|---|
| US grace period | 1 year from your own disclosure — US only |
| Most other countries | No grace period — file before disclosing |
| Priority period | 6 months for designs, not 12 |
| Publication | At grant, not at 18 months |
| Term start | Grant — so pendency costs nothing |
The six-month priority period catches people who assume the utility patent timeline applies.
Trade show disclosure before filing abroad is the common way design rights are lost.
Outside the US
| Jurisdiction | Term | Renewal |
|---|---|---|
| United States | 15 yrs from grant | None |
| European Union | Up to 25 years | Every 5 years |
| United Kingdom | Up to 25 years | Every 5 years |
| Japan | 25 yrs from filing | Annual fees |
| China | 15 yrs from filing | Annual fees |
The US is unusual in requiring nothing. Most jurisdictions charge renewal fees, which reintroduces the attrition the US system avoids.
A global design portfolio therefore needs the same administration as a utility one, even though the US members do not.
Costs across the life
| Item | Design patent | Utility patent |
|---|---|---|
| Official filing fees | Lower | Higher |
| Drawings | The main cost | Supporting |
| Prosecution rounds | Usually fewer | Often several |
| Maintenance fees | $0 | Up to $14,470 |
| Renewal decisions | None | Three |
Lifetime cost is a fraction of a utility patent, which is why filing several design applications on one product is affordable in a way that filing several utility applications is not.
Common misconceptions
| Belief | Reality |
|---|---|
| "Design patents last 20 years" | 15 from grant |
| "You have to renew them" | No fees at all |
| "The term runs from filing" | From grant |
| "They protect the function too" | Appearance only |
| "Broken lines are drawing errors" | Deliberate disclaimers |
| "One application covers the product" | Several, each claiming a portion, is stronger |
The renewal misconception costs assets in reverse — owners occasionally abandon design patents believing a fee is due.
Patent of design: the checklist
- It protects appearance only. Function needs a utility patent.
- The drawings are the claim. Treat line types as claim drafting.
- Use broken lines deliberately to disclaim and broaden.
- Consider several applications on one product, each claiming a portion.
- Test for functionality — do alternative shapes work equally well?
- Expect the ordinary observer test, not element-by-element comparison.
- Remember §289 allows recovery of total profit on the article.
- Mark products. Marking rules apply as they do to utility patents.
- File before disclosing. The priority period is six months, not twelve.
- Budget nothing for maintenance. There are no fees, and the patent runs full term.