The technical problem
The integration of a fragrance on paper substrates, however, presents significant technical challenges for the formulator and the printer’s R&D manager:
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Olfactory duration incompatible with the product's life cycle
A fragrance applied in free form on paper evaporates rapidly - normally within a few days - making the product olfactorily inactive well before it has exhausted its communicative or educational function. -
Instability during the printing process
Free fragrances are volatile substances sensitive to heat, with risk of degradation or partial evaporation already during the production phase. -
Uncontrolled fragrance dispersion
A fragrance applied in free form spreads spontaneously into the environment, making it impossible to control the timing and intensity of olfactory release and creating potential issues in contexts such as libraries, offices or school environments. -
Compatibility with industrial printing processes
The solution had to integrate into the screen printing and flexographic processes already in use at the printer, without requiring dedicated equipment or modifications to the production line.
Analysis of options
During the technical evaluation phase, IPS identified scented Capsular Ink as the most suitable technical solution for this type of application, within the broader range of microencapsulated Capsular Ink.
Unlike a fragrance applied in free form, scented Capsular Ink incorporates the fragrance inside microcapsules with a core-shell structure: the core contains the protected fragrance, while the polymer shell isolates it from the external environment, preventing spontaneous evaporation. Release occurs exclusively through direct mechanical action – rubbing or pressure – which breaks a portion of the microcapsules present on the printed surface.
This mechanism structurally solves all three technical criticalities identified: the olfactory duration becomes extraordinarily long – samples of prints produced with this technology retain perceptible olfactory traces even years after printing – the fragrance does not disperse spontaneously into the environment, and the microcapsules withstand the thermal and mechanical stresses of the printing process.
The technology: scented Capsular Ink by IPS
Scented Capsular Ink is a functional ink that incorporates microcapsules with a core-shell structure containing fragrances protected by a polymer shell. During the printing process, the microcapsules are deposited on the paper substrate together with the ink vehicle and remain intact until mechanical activation by the end user.
The microencapsulation technology underlying Capsular Ink ensures that the fragrance is preserved intact for years after printing, retaining the original olfactory intensity until the moment of activation. Since thousands of microcapsules per square centimetre are present on the printed surface, each rub breaks only a small fraction of them – ensuring a very high number of activations before complete depletion.
Technical parameters relevant to this application:
| Value | |
|---|---|
| Product type | Microencapsulated ink with fragrance |
| Release mechanism | Mechanical activation - rubbing or pressure |
| Compatible printing techniques | Screen printing (preferred), flexographic printing |
| Compatible substrates | Paper and cardboard (including coated), PET, PP, self-adhesive labels |
| Olfactory duration | Very long - years from printing under standard conditions |
| Spontaneous dispersion | Almost absent — release only through mechanical activation |
| Fragrance customisation | Wide library available; possible microencapsulation of fragrances supplied by the customer |
The application process
The scented Capsular Ink is integrated into the printing process as an additional step – generally one or more dedicated screen printing passes – applied to the area of the postcard, card or other element intended for olfactory interaction.
The scented area can coincide with a specific graphic element or cover the entire surface of the support.
Once printed, the material is immediately ready for distribution.
The end user activates the fragrance by rubbing a finger on the printed surface, progressively breaking the microcapsules and releasing the fragrance into the surrounding environment in a controlled and non-invasive manner.
Compatible printing techniques
Screen printing is the preferred technique for scented Capsular Ink on paper substrates: it allows thicker layers to be deposited with a higher density of microcapsules per unit of surface, maximising the perceived olfactory yield for the user at the moment of rubbing.
Flexographic printing is compatible with large-volume production – a relevant feature for printers working on high print runs in the postcard, direct mailing and promotional materials sector – with attention to printing pressure control to preserve the integrity of the microcapsules.
Schematic overview of the process
- Definition of the scented printing area on the paper substrate
- Screen printing or flexographic printing with scented Capsular Ink and the selected fragrance
- Drying with standard process - the microcapsules withstand thermal stresses
- Finished product: printed material with microencapsulated fragrance ready for activation
- Distribution and use: rubbing → microcapsule breakage → controlled fragrance release
- Repeatable activations over time thanks to the high number of microcapsules per cm²
Applications by sector
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Publishing and educational products
Illustrated children's books with interactive olfactory elements - flowers, fruits, foods and many others - where microencapsulated fragrance enriches the reading experience with an additional sensory stimulus. Scented bookmarks for libraries, bookstores and educational institutions. Educational materials for sensory education in preschool and primary education. The fragrance does not disperse spontaneously, eliminating any compatibility issues with school or library environments. -
Direct marketing and promotional communication
Scented cards for direct mailing campaigns - a format that significantly increases the message's open rate and memorability compared to a conventional card. Promotional postcards for product launches in cosmetics, perfumery, food and detergents, where the product's fragrance can be anticipated through the promotional material itself. Invitations and materials for events with a themed olfactory element. -
Cosmetics and perfumery
Olfactory samples printed on cardboard - scented strips - for the communication of new fragrances at the point of sale, in magazines and promotional materials. Microencapsulation ensures that the fragrance is preserved intact until the moment of activation, unlike conventional strips that evaporate rapidly. -
Packaging and point of sale materials
Scented cards inserted in the packaging of cosmetic products, air fresheners or other products where olfactory communication adds value. Scented POP and display materials for point of sale in the packaging and design sector.
Results and benefits
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Extraordinary olfactory duration
The protection of the microcapsules ensures the fragrance is perceptible for years after printing - a decisive advantage over any solution with free fragrance. -
Controlled and non-invasive release
The fragrance does not disperse spontaneously into the environment but is released only through direct mechanical activation, eliminating any compatibility issues with enclosed spaces such as offices, schools or libraries. -
Repeatable activations
Each rub breaks only a fraction of the microcapsules present, ensuring multiple activations before depletion - a user experience repeatable over time. -
Stability during production and storage
The microcapsules withstand the thermal and mechanical stresses of the printing process and keep the fragrance intact throughout the entire pre-distribution storage period. -
Extensive fragrance customization
IPS has a library of fragrances tested and validated for microencapsulation — floral, fruity, herbal, spicy, woody, gourmand, fresh — with the possibility of microencapsulating fragrances supplied directly by the customer, subject to compatibility verification. -
Immediate compatibility with the existing printing line
No modifications to the equipment - Capsular Ink integrates as an additional step into the screen printing or flexographic process already in use.
Target sector and related applications
This application falls within the field of functional printing with microencapsulated inks and sensory packaging, with a specific application in the publishing, promotional and educational sector.
Related applications developed by IPS in the same area include scented labels for packaging of air fresheners and home fragrance products, photosensitive inks for cards and interactive UV promotional materials, and thermosensitive inks for interactive packaging and educational materials with reversible chromatic effects.
To assess the technical feasibility of new sensory printing applications on paper substrates, IPS offers a structured development and prototyping service: fragrance analysis, microencapsulability verification, printing tests and optimisation of process parameters. For information or sample requests, you can contact the IPS team directly.
