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Printer ink not black in IR

asked 2020-04-02 09:44:14 -0500

CarlEmail gravatar image

updated 2020-04-02 12:37:17 -0500

The black tiles on my chessboard are not so black when viewed through an infrared camera. Why so?

The board is printed using a regular Cannon ink printer. Should I go hunting for a laser printer? What are my options if I want my IR camera to see printed black?

EDIT: I found that the IR wave length is 850nm. Still looking for a solution though. https://docs.microsoft.com/en-us/azur...

All the best Carl Emil

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Try shining an incandescent light on the paper. That should help distinguish the light and dark parts, though I don't know if it will be enough.

Tetragramm gravatar imageTetragramm ( 2020-04-02 14:50:13 -0500 )edit

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answered 2020-04-20 08:49:34 -0500

CarlEmail gravatar image

updated 2020-04-20 10:48:28 -0500

HOLY COW! I made a print on a regular laser printer and it comes out great. Apparently laserprint is great for 850nm light.

Inkjet(top) vs. laserprint (bottom).

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answered 2020-04-02 12:19:59 -0500

crackwitz gravatar image

most important question: what wavelength does your IR light have?

https://en.wikipedia.org/wiki/Infrared#Regions_within_the_infrared

apparently the ink from your printer absorbs visible light (you see it's black), but infrared only barely (nearly as bright as plain paper in your IR image).

you need something that absorbs your infrared illumination. "carbon black" is commonly used. take the soot from a lit candle to blacken the surface (a stencil may be involved). there are also inkjet inks that absorb infrared. I don't know if toner from a laser printer would work.

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The wavelength is 850nm. I am not sure how to get my hands on a printer that support IR ink locally (Copenhagen). https://docs.microsoft.com/en-us/azur...

CarlEmail gravatar imageCarlEmail ( 2020-04-02 12:35:55 -0500 )edit
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IR-absorbing "black" ink should be as simple as finding a cartridge for your printer, then swapping it in for normal black.

crackwitz gravatar imagecrackwitz ( 2020-04-03 18:55:08 -0500 )edit
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when I needed to calibrate RGB to thermal infrared, we used a wooden board with a pattern of screws/nails and heating wire. the screws were blackened for contrast in RGB/visible spectrum, but heated to be visible in (thermal) IR. 850 nm is very close to visible so you might only start to see hot metal in your IR camera when it's almost visibly glowing (entering visible spectrum). thermal IR is far longer wavelengths.

crackwitz gravatar imagecrackwitz ( 2020-04-03 18:57:26 -0500 )edit
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Asked: 2020-04-02 09:44:14 -0500

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Last updated: Apr 20