Mounting a really blue print


MGF, Master Grumble Framer
Jan 5, 2002
annapolis, md., usa
I have a couple of "blue" prints that aren't the same as most blueprints I've seen. These are detail drawings of the Lightning sailboat (great little boat!). The customer who brought them in said her father was the designer, but these are not original drawings. The paper is dark blue, each sheet about 26 x 36. She wants them dry mounted.

Most blueprints and construction drawings I've worked with are on paper about the same weight (very thin) but pretty light in color. Any idea how these will react to heat? Of course, I'll do a little heat test. Conservation is not an issue here and mounting with my heat press using tissue or speedmount is what we are considering.
I haven't mounted a blueprint in years, so I don't remember EXACTLY how well they took the heat, though as I seem to recall, they weathered the heat press pretty well. To be sure, someone more experienced than I might pipe in on this. However, I do recall vividly that the biggest problem with the blueprint paper was that it did not like to stay stuck. In very short order, bubbles would form under the paper after they were framed. I think there's something in the paper, like maybe some sort of oil (?) that makes it resistant to the adhesive.

Perfect Mount foam core might be an alternative, but again, you may have the same issues with adhesion. Good luck.

[ 02-12-2004, 11:38 AM: Message edited by: AndyPan, CPF ]
I accidently heat mounted a blue print years ago and the whole thing turned bright blue......proceed with caution....
I believe that the developing process for true "blueprints" is heat activated, so dry mounting should be avoided. I think it is a form of cyanotype.
On the other hand, these may be decorative prints done as an offset lithograph to look like a blueprint. I remember seeing something like this in the early 70's and they were poster quality.
Let the edge of the print hang off the edge of a table about 1/8" and touch a hot tacking iron (with the sole turned to vertical) to the edge to check for heat reaction.
Thanks all. I thought I read something about the color change associated with heat. A bit foggy to me (which means I could have read it yesterday), so I appreciate the confirmation. Interesting read Rebecca. I'll do a test but sounds like I might use Printmout to avoid heat and the adhesion problem Andrew experienced.

Older blueprints will change color with heat and are extraordinarly sensive to light, too.

I speak from sad experience.
So far this evening, we've had a 'dirty' picture that turned out to be soiled and a 'blue' print that is actually a blueprint.

I'm so disappointed.

I have a 1916 blue print of the property we own which I dry mounted in our heat press with fussion 4000 10 years ago. Seems to be just fine, however it was not that of a customer.
I would cold mount that blue print. I used to operate a real blue print machine around 1993 (they were being used less and less then) and they required heat to produce them.

In addition, I believe I read somewhere that you should only use unbuffered photorag for real blue prints... I believe they may be alkaline sensitive.