UV logo printed on 'optically DULL' paper

apoziopeza

Senior Member
slovak
Hi,

Please help

does "dull" mean clean (unwritten) in the context below?

thanks,

A.
Context/ source -

Chamber of Commerce
Commercial Register
extract


A certified extrac is an official proof o rregistraion in the Commercial Register. Certified extracts issued on paper are signed and contain a microtext and UV logo printed on "optically dull" paper. Certified extracts issued in electronic form are signed with a verifiable digital signature.
 
  • entangledbank

    Senior Member
    English - South-East England
    Security paper has hidden features in it, such as invisible fibres that fluoresce under UV light. 'Optically dull' apparently means that the rest of the paper doesn't fluoresce under UV, so that the hidden fibres show up clearly. Source: https://docs.google.com/viewer?a=v&q=cache:buvOjFMvJUYJ:www.qt2.com/SECURITY%2520OPTIONS.pdf+optically+dull+paper+-agn&hl=en&gl=uk&pid=bl&srcid=ADGEESiHWypF7sITh5mHHS1we6kXvQAYS0vSYnhxIn0usC4x60eqIjBJwhs-YkB_7yOFH0lJx9e0vUi0gsoawjTPAwcCGrKe1lx7vWnI0Bpye9REvGPivoqbu7RfRv51ZO4HBKia-zRy&sig=AHIEtbT7B3SoJeVe5wzYhtyJF53u0tM8Wg (Quick View of a .PDF from www.q2.com)
     

    audiolaik

    Senior Member
    Polish
    Hi,

    Here's what I've managed to find:

    Security paper needs to be optically dull or dead (have little or no fluorescence) to allow the needed contrast to print with invisible inks and to allow invisible fibers to activate under black light. This will verify document authenticity. Optically dull paper is a standard item used on all checks without upcharge. Optically dead paper must be requested and a small upcharge applies.
    source: http://www.qt2.com/SECURITY%20OPTIONS.pdf

    A&AJnr
     

    apoziopeza

    Senior Member
    slovak
    I have managed to find this - and it suggests that its synonym is optically unfluorescent or optically inactive The problem is that when I cannot translate it I at least try to translate its synonym. In Slovak there exists a term which literally says opticallly fluorescent. So I will negate this term :)

    A.


    ABSTRACTWe investigate why half of X-ray–selected active galactic nuclei (AGN) in deep surveys lack signsof accretion in their optical spectra. The majority of these “optically–dull” AGN are no more than​
    ​
    6 times fainter than their host galaxies in rest-frame R-band; as such, AGN lines are unlikely tobe overwhelmed by stellar continuum in at least half the sample. We find that optically–dull AGNhave the mid–infrared emission and Lx/LIR ratios characteristic of local Seyferts, suggesting that thecause of optical dullness is not missing UV–optical continua. We compare the morphologies of 22optically–dull and 9 optically–active AGN at 0.5 < z < 0.8, and find that optically–dull AGN showa wide range of axis ratio, but optically–active AGN have only very round axis ratios. We concludethat hard X-rays select AGN in host galaxies with a wide range of inclination angle, but only thoseAGN in the most face-on or spheroidal host galaxies show optical emission lines. Thus, extranucleardust in the host galaxy plays an important role in hiding the emission lines of optically–dull AGN.[This manuscript uses low–resolution figures. A full–resolution manuscript can be obtained at
    http://satchmo.as.arizona.edu/~jrigby/optdull.ps]
     
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