Dry press mounting temperature

[Ryan Mack]

Somehow yesterday when I dry press mounted a gloss pigment print onto foam board it ended up dramatically reducing the d-max of the image... bad enough I binned it. I'm not sure if it was insufficient drying time after printing, the foam board offgassing something, or my press running too hot. In any case, I decided to recalibrate the press and make sure the thermostat isn't sticking.

I figured I should check with the group what they recommend for temp settings. I use Dry Lam Colortac Dry Mounting Tissue which has a recommended temp of 178°F and a min of 168°F and a dwell time of 2 minutes. Should I try to keep it down in the 168-170°F range and possibly let it sit longer? Or should a pigment print be OK up at 178°F? I'm using Canon Lucia Pro if it matters.

Also, while writing this post I noticed that it looks like Dry Lam Colortac Dry Mounting has been discontinued. Anybody have another brand they recommend? The other products still listed on B&W are all the way up at 185-210°F!

[datro]

I have always preferred ColorMount tissue for both fiber darkroom and inkjet prints (and still have some here for the occasional inkjet print that I want to dry mount) but I think it has also been discontinued.  My backup would be the D&K RagMount Tissue.  It's supposed to be specifically designed for inkjet substrates and is low temp.  I've seen it at Blick, Talas and B&H.

Regarding temperatures:  I run my Seal (now D&K) dry press at 225 degrees (on the dial) and press for 2 minutes 15 seconds for a 4-ply Rising 24x29 board with 16x20 print on Canson Rag Photographique.  It is sandwiched between top and bottom 24x29 boards, so there is a LOT of board to absorb the heat.  All boards are pre-heated for 1 minute in the press (closed but not locked) to drive out moisture before pressing.  The print should also be pre-heated (30 sec.) before tacking the tissue to it, again to get rid of moisture.

There are a lot of variables in dry mounting:  board size, board weight/density, print paper size and base material (cotton, etc.), moisture content, etc.  The BEST way to determine your time and temp for a given board size, materials and sandwich setup is to use a temperature indicator strip.  Seal used to make these specifically for their dry mount presses but I don't know if anyone makes these anymore.  Basically it has several waxes on it that melt at specific temperatures.  You put the strip in a "test" sandwich for your target time and then determine which waxes melted.  From this you can then adjust temp up or down as needed to get to your target for the tissue being used, or probably better, adjust your time as long as you don't go below about 2 minutes.

In general it is best to give more time rather than more temperature when there are dry mounting binding issues.  But you do need to make sure the print/tissue layer in the sandwich is getting at least the heat needed to properly bind to your substrate.  In your case it sounds more like you somehow got too much heat.

Was the print (ink) allowed to fully dry before mounting?  Was it RC or fiber based paper?