Ilford MGIV RC gloss - "gloss differential"?

[alkos]

I have noticed that deep blacks (i like to print this way) on glossy RC prints handled against the light become lighter, as if they reflect more light than the rest of the print.

Yesterday I've tried Silverprint Proof paper - supposedly inferior product to MGIV, however also made by Ilford (afaik) - and it did not display this effect.

Is it something inherent to MGIV, or more papers? I quite often print on grades 3,5-5, so the Silverprint Proof is not an option.

Should I expect this from Foma RC glossy?

Is there anything I can do to minimise the effect? Like dev type?

 

[Nicholas Lindan]

RC paper exhibits a 'haze' that veils the blacks if you hold the print against the light at an angle. Early RC papers were much, much worse than MGIV RC, if that is a consolation. The haze can can sometimes be lessened by putting the print in a print dryer for a few minutes.

The haze, and reflections in general, are more noticeable in the black areas because there is more image:reflection contrast.

The pearl finish doesn't exhibit the same problem and I rather prefer it for that reason.

 

[Neal]

Dear alkos,

I find that forced drying with a hair dryer reduces the "veiling" effect that is, what I think, you might be seeing. Ctein noted in Post Exposure that an IR dryer removes it completely, but few of us have one of those. He also noted that the problem was worse with a non-hardening fixer, but I can't personally verify that. A word of caution, if you aren't careful you can cause the plastic substrate to melt (yes, personal experience). Keep the dryer moving over the print to avoid that problem.

Good luck,

Neal Wydra

 

[polyglot]

I use MGIV RC Pearl (44m) and can't see that effect on the prints I have here. If it's what I think you mean, it's a specific case of metamerism and is a classic problem with inkjet on matte rag because the (dark) ink once dry is more reflective than the photorag it's applied to. Under diffuse light, the ink looks darker but with specular light, the ink looks lighter due to its reflectivity.

Negatives have a similar effect when viewed at the right angle. Daguerreotypes and tintypes, while being negative, can look like positives for the same reason.

 

[alkos]

Thanks guys.

Do you know what is the safe temperature for drying RC paper? I am thinking about modyfying A4 laminator (dimmer connected to the heating element) to make it suitable for drying my 8x10 workprints... too much work & noise with the hair dryer

 

[BobNewYork]

I don't use RC Glossy for this very reason. I use RC for pilot prints and proofs - or prints people ask me, (usually as a "favour") to just "print one off for me." I use the pearl or similar finish as it most closely resembles the glossy, unglazed finish of fibre-based, whihc I use for my "serious" work.

Bob H

 

[Konical]

"Do you know what is the safe temperature for drying RC paper?"

Good Morning, Alkos,

The Seal test strips used to set the press temperature for dry-mounting correctly indicate that 200 degrees is safe but 210 degees is too hot.

Konical

 

[alkos]

Thanks Konical - I assume you mean Farenheit, so 94 / 99 Celcius?

Meanwhile I have bought cheap laminator + simple dimmer and DIYed it into a print drying machine ;-) (removed thermostat switches and "dimmed" the heater only) On 85 deg Celcius a squeeged print comes out almost completely dry - with no gloss difference in shadows! (if I run it through second time, slight warping occurs)

Thanks for all your advice!

 

[Konical]

Good Evening, Alkos,

Your assumption about Fahrenheit is correct. I've forgotten the conversion formula, so I'll assume that your Celcius figure is correct.

Konical