Black fluorescent inks developed for postal applications exhibit contrast suitable for machine reading and fluorescence suitable for postal processing. The combination of black color and red fluorescence in one ink requires inhibition of fluorescence quenching. One way to inhibit quenching is by combining subtractive dyes and leaving an absorbance window for the emission of the red fluorescence. The absorbance and emission spectra of the ink confirm the model. Another approach is combining larger size colorants: fluorescent and non fluorescent in order to lower the collision probability and quenching by energy transfer. The covert nature of the fluorescence lends itself to security applications.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.