Posts Tagged ‘engineer’

Questionable Rolls From Flavor Paper Today

April 16, 2023
It’s important that all your rolls of wallpaper be of the same run , or batch number , also called dye lot . This ensures that the rolls were printed at the same time with the same batch of ink . Rolls printed from different batches or runs could be a very slight different color or shade – and that can result in a striped effect on your walls .
The run number is usually printed on the label of the wallpaper. But since Flavor Paper doesn’t use traditional labels, they put a tiny sticker with the run number onto the outside of the plastic bag that each roll is slipped into. These stickers aren’t particularly secure, IMO.
On this job with the Brooklyn Toile pattern from Flavor Paper , we needed eight of their “rolls.” Each roll contains two strips , printed in one long sheet that you cut apart in the middle to separate the two strips .
Flavor Paper comes with a header at the top of the roll, that includes the pattern name and other information from the manufacturer . In this photo, I’ve cut off that top portion.
We had six rolls that came like this.
But then two rolls came like this, with that top part removed.
In addition, this paper has been damaged and soiled . Not smudges around the birds near the center .
I suspect it was purchased by another homeowner, the installer removed the top header , then didn’t need the roll, and it was returned to the manufacturer . In the process, it got beaten up and dirtied.
Here’s another shot of the header missing. If the previous installer had a pasting machine, he could have used its built-in cutter to make a perfectly straight and 90* angled cut like you see here. That’s another reason I think it was opened, not used, and returned to the company.
This is the second roll. Look at how it’s been wrinkled and damaged . Paper doesn’t come from the factory like this. It had to have been unrolled, re-rolled, and put back into the plastic wrapper.
Even worse, a couple of feet into the second roll I came upon this badly creased wallpaper . This crease was probably caused by the factory . But it could also have happened at the hands of the other (alleged) installer .
Because of the way this material is printed and packaged , not in continuous rolls like most brands , but in panels or strips that are 24″ wide x 10′ 4″ long , with a somewhat long pattern repeat , I was not able to simply roll off a pattern repeat or two and still get a strip long enough to fit the wall. In other words, this damaged strip cut me short of what I needed to wallpaper this powder room .
Here’s another reason why I think these two rolls were opened and then sent back to the manufacturer . That one on the right looks like it’s been opened , unrolled , and then re-rolled – and when you do that, you can never get the roll to be as tight as it was when it came off the factory line.
I think these two odd rolls were purchased, not used, sent back to the company, and then simply stuck on a shelf to be resold – without anyone ever checking to see if they were in good condition.
Or what the proper run number is.
In addition, I don’t have confidence that the run number that was on that little sticker on the outside of the bag (see caption to top photo) is actually the right number.
In the end, I was able to futz and fiddle and engineer – and get the room done with the paper that was useable.
In the meantime, the homeowner is communicating with the manufacturer. Flavor Paper has good customer service . Additionally, they are members of the Wallcovering Installers Association / WIA (as am I).
This pre-pasted material is in their EZ Papes line, which I like a lot. I am not fond of their vinyl or peel & stick materials , and some of their papers can be darned tricky to install. I ask my clients to stick with the EZ Papes.

Grasscloth Engineering and Logistics – Technical Details Post

August 21, 2022
Grasscloth is a natural material that cannot be matched from strip to strip, so all the seams will be visible . In addition, there is usually a slight but noticeable color difference between strips / panels (called shading or paneling ) . So it’s important to plot the layout of the strips to give the most visually pleasing overall look. Usually this means balancing the width of strips so they are all equal , at least on the same wall . We call this engineering .
This wall presented particular challenges , due to the widths of the elements. Grasscloth comes 36″ wide . You can use your straightedge and a sharp razor blade and trim it down to any width you want.
The width of both the large wall spaces to the right and left of the bank of windows was 34.” The width of each window was about 35.” The width of the two spaces in between the windows was 7.”
So you’d think I could trim my panels on either side of the windows, and then over the windows, to about 34″-36″ – give or take a few inches (or fractions thereof).
But that would leave me with two 7″ wide strips between these 35″ panels. Although the look would be uniform and mirror-image from the center outward, moving from right to left you’d have: 35,” 35″, 7,” 35,” 7,” 35,” 35,” … those 7″ breaks were just not going to look right.
One option was to determine the width of the wall (189″) and make each strip an equal width. This worked out to six strips, each at 31.5″ Not good, because this would mean a seam down either far side. And since those sides were 34″ wide, that would mean a 31.5″ wide strip and a strip 2.5″ wide. Not attractive at all, and it would use up an extra strip of wallpaper.
This six strips @ 31.5″ wide scenario might also land with a seam smack in the middle of those 7″ wide interludes in between the windows. Not attractive at all.
So I decided to make the two outer strips 35″ wide. That left 119″ of wall space above the windows to be covered with wallpaper. Do some math and you get four panels of 29.75″ wide. This gave a balanced and uniform look to the area over the windows, and also prevented seams from landing between the windows.
Moving right to left, I cut and hung the full length outer strip first. Then I cut and hung the strip over the window on the right. Then I measured to find the centerpoint of the window in the middle. Turns out it was a bit less than 29.75″ away. So I trimmed that next over-window strip accordingly.
Once that was in place, I measured from that center point above the middle window out to where my left full-height panel would fall, 35″ out from the wall. Took the resulting measurement and divided by 2. Lo and behold, each of the next two panels over the window was going to be a bit wider than 30.” No problem. No one (but a paperhanger or maybe an engineer) is going to notice a 1/4″ or even a full 1″ difference in widths between this strips over the windows.
Another thing to point out … it’s important that I took measurements before cutting these strips for this second left-hand section. Because, since grasscloth comes at 36″ (and walls can be wonky), if my strips had been narrower (say, 28″), that last full-height panel on the left might have ended up needing to be 37″ wide – and that wouldn’t work because it only comes 36″ wide – plus you need at least 1/8″ to wrap around the corner.
Luckily I had the flexibility to be able to trim the panels over the windows to any width needed, to accommodate all this.
If you’ve followed all this so far, let me also toss in that we also need to figure how to get paper in between those windows. More on that below.
In this scenario, I’m moving from right to left.
Area beneath the windows needs to be treated in the same way, and preferably with widths that match what’s going on above the windows. In addition, it’s tricky because after you move across 12′ of wall space, the strips above and below the windows are going to twist and torque out of shape, so that last full-length panel on the far left might not butt up perfectly with the last strip under the windows.
The grasscloth is black , and my wallpaper primer is white . It’s common for teeny gaps to appear at the seams . In this case, it’s likely that white wall would peek out from those gaps. So I like to stripe under where the seams will fall with dark (diluted) paint . This takes measuring , plotting , and also a heat gun to get the paint to dry before the wallpaper hits it, to avoid staining. You can do a Search here to read more about this technique .
Now let’s talk about getting wallpaper in between those windows.
As you can see in the photo, if I hang a 30″ wide strip, a whole lot of paper is going to be cut off and thrown away. Also, a whole lot of sticky, pasted paper is going to bump against that window molding and maybe even the window glass. A lot to clean up! And unwieldy, to boot.
My solution was to stop the wallpaper just a little below the tops of the windows. Then I would patch in a 7″ wide strip in between the windows. This is trickier than it sounds, because, if it were a paper wallpaper, I could simply cut along a design motif and overlay the 7″ wide piece. But grasscloth is thick and overlaps don’t look good. Also grass has no design elements , and the reeds of grass don’t necessarily fall perfectly horizontal , and even if you cut everything perfectly true to square , if the window molding is a teeny bit off-plumb , then your edges won’t butt up perfectly.
So that’s a good reason for striping the black paint under where the butt join will occur.
Same thing for the sections under the windows. I measured and positioned the strips so that the top edge (which I had trimmed to be perfectly horizontal) fell between the narrowest part of the windowsill molding, for less visibility.
I admit, instead of butting the two pieces, here I did overlap the 7″ wide strip about 1/4″ onto the piece under the window, right at that narrow junction. It’s only about 3″ wide, and I figured no one is going to be examining it that closely, anyway. This saved me about a half an hour of measuring, trimming, testing, repeat, repeat.
This is my second window interlude, and by this time I had realized that it’s hard to trim stiff grasscloth around intricate moldings precisely . So I used paint to fill in the edges around the window molding, just in case there might be any gaps between the grasscloth and the molding, so you would see black instead of the white molding paint. I did this with a small sponge; if I had used an artist’s brush it would have been a bit neater and tighter to the conforms of the molding. But sometimes you’ve gotta relax and realize that no one’s going to be scrutinizing the insides of moldings below shin-level.
Area over windows finished, with drapes back in place.
Turns out this particular grasscloth is so uniform in color (quite unusual, I will add), that you can’t really see the panels , nor their equal widths , anyway. I’m still glad I took the time to do all this math and trimming.
Area below the windows, done. That last seam on the left bears some explanation, too. Moving across the top of the windows, I measured that that last strip – the full-length strip – would need to be exactly 35″ wide. It butted up nicely to the last strip above the windows.
But, due to twisting , shifting , expansion , unlevel and unplumb walls and ceilings , and other factors, there is a really good chance that that last 35″ wide strip would not butt up perfectly with the last 30″ wide strip under the window . So I planned to splice these last two strips together.
Yeah, the drapes are hanging there, I coulda overlapped the two strips about 1/2″ and the drapes would have covered it. With a thin wallpaper, I probably would have done this. But grasscloth is thick, and an overlap would be visible , and also the adhesive / paste can’t be trusted to adhere as well to grass as it would to paper .
So I plotted for a splice. Instead of trimming my last strip under the window to 30″ (read above), I trimmed it to 32″ wide. That way, when I hung the last full-length strip to the left, which was 35″ wide, it overlapped the piece under the window by a few inches. Then I did a double cut and spliced the two pieces. See below for details about that technique.
Grasscloth is 36″ wide, and this wall area is wider than that. So two strips were needed. This means you’re going to have a seam, and since grasscloth seams are always visible, it looks best to plot to have the seam fall down the center. It uses more wallpaper to do this, but it looks much better than having, for example, a 36″ wide strip next to an 8″ wide strip.
As mentioned above, in case you get thin gaps at the seams, a dark stripe of diluted craft paint under where the seam will fall, will prevent white wall from showing through.
Rounded / bull-nosed edges and corners have been popular in new construction for at least 10 years. I wish they’d go away. They’re very difficult to trim around, and hard for the paper to conform to and adhere to.
It’s very hard to trim around that rounded edge, because the paper is hanging over and blocking your view, because grasscloth is thick and stiff and your fingers can’t feel through it, and because the edges aren’t necessarily true and plumb so a laser level or other level won’t help you much.
I use this little gadget as a trim guide. It’s actually a small section of the same corner bead material that drywallers use when they assemble these walls. Cut to about 1″ long and notched in different places where you might trim along the edge of the wall.
It’s intended that you place your trimming knife in one of the notches and slide the gizmo along the edge and make your cut. I find that awkward and also inaccurate. So I prefer to use the notches as a guide and mark where I plan to trim with a pencil. Since this wallpaper is black, I used this marking pencil from my home sewing kit instead. Chalk might work, but I was afraid it might now wipe off completely.
The pink pencil line was barely visible, but it was enough for me to use a scissors to trim along the grasscloth. I like this better than using a razor blade as I can see better, and also less chance of scoring into the primer or wall. Which raises its own set of issues – do a search here to find previous posts.
Inside view of the trim guide.
Finished arch. Note the four panels of equal width above the arch. And two flanking full-height panels also the same widths.
I was lucky that there was no pattern to match, so I was able to butt my two flanking strips right up to the edge of the bull-nosed corner. No trimming needed! Then I measured the remaining width between these two strips (the area over the arch), divided by four, and cut four strips of equal widths.
I hung the two on the left, and then one on the far right. This left one strip still to be positioned to the right of center. So the pieces are going to meet over the arch, rather than the last strip falling in a corner.
Same as the last strip under the window (discussed above), it’s really difficult to get your last piece to fit in here perfectly. I’ve done it, but it takes a lot of measuring, trimming, testing, retrimming, and often starting all over again.
So I did a double-cut / splice.
A double cut involves cutting each strip an inch or so wider than it should be, and overlapping the two. Then you take a straight edge and sharp razor blade and cut through both layers. This handy tool is a wonderful non-slip guide for this process. It was invented by an installer colleague in the Wallcovering Installers Association ( WIA ) and she has them fabricated in various lengths (along with other cool tools ) and sells them on-line. Contact me if you’re interested.
Anyway, it takes a lot of strength to cut through two layers of grasscloth, so somewhat difficult for lil’ ol’ me.
You also want to be sure to not cut / score into the wall, because the tension of drying wallpaper can tug at the wall and cause it to actually come apart, leaving an open seam that’s difficult to repair.
So you’ve got to put some padding under the wall where the cut will take place. I use special strips of polystyrene (hard but flexible plastic) to pad the wall. Also invented by a colleague in the WIA , who also sells other cool tools and supplies. Contact me if you’re interested.
This black grasscloth was printed on a white substrate. If the seams aren’t absolutely tight, there can be worries about the backing showing through to the front. So sometimes we’ll take a piece of chalk or pastel (never oil pastel or permanent markers because they bleed and stain ) and run it along the edge of the paper – from the back, and taking care to not get chalk on the surface.
I do this frequently with dark papers ( do a search here to see previous posts ) but opted not to do it with this grasscloth. It wasn’t necessary, and might have stained the porous reeds of the grass. It was beneficial, though, to have striped dark paint on the wall under the seams, as mentioned above.
Ugh. Grasscloth comes 36″ wide, and this section of wall is 38″ wide. It’s not visually pleasing, nor is it easy from an installation point of view, to have a 36″ wide strip next to a 2″ wide strip. Or to use scraps and put a 25″ wide strip next to a 13″ wide strip.
So best to plan two strips of equal widths. Two strips, each 19″ wide, with the seam down the middle.
Actually, the strip on the left was 19″ wide, but I trimmed the strip on the right to 21″, because I like the wallpaper to extend 2″ over the top of the door molding. This provides a more stable surface in case of shifting foundation or walls, and less likelihood (knock on wood) of the seam opening up should the house / drywall experience shifting.
Note that design “rules” caution against seams down the middle of spaces. But it would have been more visually distracting (and used up more paper) to have made three strips of each 12.75″ wide. And would have looked even dumber to have used scraps left from other walls and put together two strips of disparate widths.
So the homeowner and I discussed during our initial consultation , and she was happy with the center seam. Once it was all finished, this particular grasscloth was so even in tone that you barely see the seams, anyway. Win-win!
This did use up additional paper, though, as noted in a previous photo above.

Saving Paper, Right and Left

August 16, 2022
Here I’m hanging wallpaper , moving from left to right. The wallpaper is 21″ wide . The width between my last strip on the right and the wall is 15″.
That means that I will have to cut off 6″ width of paper – which usually ends up on the trash pile. Here I am using a straightedge to cut that off.
Since that strip of wallpaper is 9′ long, we’re losing 4.5 square feet just in this one small area.
(Another reason to always buy a little extra wallpaper … you can’t use every square foot !)
Note that I’ve actually cut my strip to 15.5″, so I’ll have a little excess for trimming at that right wall.
Back to that 6″ (actually 5.5″) wide strip on the trash pile. I never throw anything away until the job is finished. Because I just might be able to use a piece somewhere. As in this case …
After the right side of the wall was finished, I started moving to the left. When I came to the left corner, my last strip needed to be 1.5″ wide.
Instead of cutting a whole new 9′ long strip off the roll of wallpaper, I reached for that scrap pile and pulled out that narrow 5.5″ piece that had been trimmed off the opposite edge of that strip on the other side of the wall.
This was the correct pattern match to meet up with the strip on the left side of the wall in the photo above.
Here I am trimming a 2″ strip (1.5″ + .5″ for trimming allowance) off the appropriate edge of that scrap piece. Note: Be certain you are trimming from the correct side of that scrap! Or the pattern won’t match and you’ll have to cut a fresh 9′ length after all. 😦
Here the wall is finished. For the two corners, only one strip was used, due to being able to cut both a right and a left piece out of only one strip of wallpaper.
Now I’m going to get into a little more technical stuff, that usually only a paper hanger will understand. The pattern above is what we call a straight match . This means every strip is the same. And that a particular design motif (like the pink flower) hits the top of the wall at the same position on every strip. My right-left trick above only worked because this was a straight pattern match.
But … you can make it work with a drop pattern match, too. A drop match means that every other strip is the same. On a drop match, the pink flower will be at the top of the wall on one strip, but drop down a few inches (half the length of the pattern repeat ) on the second strip. By the third strip, it will be back up at the top of the wall.
This also leads to using A and B strips. Confusing – but we wallpaper installers get it.
Anyway, my trick explained above works for straight matches, with all A strips. But if your right corner of the wall ends in an A strip, and the left corner needs a B strip, your scrap from the A strip won’t match the pattern repeat needed on the left side of the wall. So you’re gonna have to cut a whole new 9′ long strip, just to cover that 1.5″ gap at the left corner.
But – WAIT! – there is a trick to outsmart this. If you plan ahead, and count your strips, and plot the layout, and engineer your project, you can avoid needing that 9′ long strip.
When you’re cutting off from the bolt that last A strip for the right corner, just cut it a little longer. Cut it long enough to include the B pattern match. Do a little math and then do some visual checking to be sure you’ve got it right. Then cut your strip.
When you get to trimming off the 15.5″ wide right edge, it will be a few inches longer than the previous strips. So you’ll throw away a tiny bit more when you trim at the bottom of the wall than if it were a straight match.
Correspondingly, the 5.5″ wide scrap left over, from which you will cut the 2″ wide strip needed for the left corner, will be a few inches longer at the top of the wall than needed.
So by juggling the A & B pattern match / repeat , you’ve saved a whole 9′ long strip. This is good, because you always want a bit left over, in case of need for repairs down the road.
This fun pattern is by Missoni Home , which is made by York . It’s a textured embossed vinyl on a non-woven , paste the wall backing and was a very good paper.
Houston