Different Runs – Different Materials

Due to a mix-up in terminology, the homeowner originally received just four single rolls (two double roll bolts ) of wallpaper .  They needed eight total single rolls (four doubles ), so two more double roll bolts were ordered.  Being unable to get the same run number , we anticipated a slight difference in shade .  But didn’t expect that the two new bolts would be thinner than the two original bolts . 

What the heck is up?! 

The selection book says this is a non-woven product, and a paste the wall installation method .  Yet the label on both the original and the new rolls says to paste the paper.  Even more puzzling, the instruction sheet included inside the rolls says that it’s  non-woven material , and to paste the wall. 
It’s important for the installer to know what material he’s working with, so I needed to know if this was PTW or PTP .  Usually, non-woven paste the wall are thick and hard to tear , due to their 20% polyester content .  The fat roll felt and acted like a non-woven .  But the thinner roll was thin and crispy and easy to tear.  I sure thought it was a paper material , which would require a different installation technique .  In recent months, I’ve had this same manufacturer send several rolls of the a particular pattern , but some were non-woven, and some were paper.  So I thought we might be experiencing this again.  It’s important to know what you’re working with, because different materials require different installation techniques.  If a DIY ‘er follows the instructions to paste the wall , but it’s actually a paste the paper material, he’s going to encounter a whole lotta mess – and ruined paper . 

Here I used my 24” wide straightedge to tear off a strip of wallpaper from the roll of thin material.  This answered my question.  See the little fibers ?  Those are indicative of non-woven papers, and their polyester content .  Once I saw this, I was certain that it was, indeed, a non-woven material / paste the wall . 

So this material was easier to hang than traditional papers, because no need to paste , book , and let sit for a few minutes.  There are other pluses, too, to NW papers, and most of us professionals like hanging them.  But I wasn’t 100% pleased with the thin version of this non-woven material.  For one thing, its stiff, crispness made it difficult to manipulate, and prone to crease . Also, notice the splotchiness of the paper.  This showed up on the dry paper, right off the roll.

But paper that has been pasted and hung on the wall showed even more splotches .  This is scary, because there is a issue called blushing or staining , where the paper looks like it’s wet , but never dries out.  Do a Search here to learn more.   This happens mostly with non-woven papers , and is tied to certain types of paste .  Which is why I don’t use those pastes!  So curious as to what is causing this slight discoloration.

I believe the spots were just due to moisture .  As I worked my way across the wall and time went on, the paper I had hung first had a chance to air out and dry.  The blotches disappeared . 
 
I’m curious as to why the difference in material.  Maybe the manufacturer was using different factories?  In different countries? Or supply chain issues / material shortages meant that their usual substrate and inks were not available .  Or just trying to cut costs?  Saving money isn’t a bad thing.  But it is, if it cuts down on the product’s quality.