MOAB Road Test

It was only a coincidence that we chose the hottest day of the year to road test 'Desert Varnish' by MOAB®. It was 93° in the shade... pushing the limits when it comes to spraying coatings onto giclées. But that is what road tests are all about, pushing things -- but hopefully not off the cliff.

Desert Varnish is MOAB®'s contender in the giclée coatings wars. Until recently there weren't many choices but now there are several. I've already reviewed two others -- Clear Shield by Clearstar® and Premier® ECO Print Shield -- in previous blogs.

Secretly, I was hoping that the MOAB® product would do well because it is readily available here in Seattle at Glazer's Camera. The other products are gotten either online or at Tricera Imaging in Vancouver, Canada ...each equally inconvenient. Moreover, I had met MOAB's Seattle product rep, Tom York, at the NW Photo Festival and he seemed like a nice guy. I was there selling my book, Giclée Prepress - The Art of Giclée and Tom was nice enough to put a copy on the table at his stand for Legion Papers® and MOAB®.

When purchasing Desert Shield at Glazer's Camera (three 1-pint bottles) I initially was surprised to learn that the product is lower priced than its competitors on a volume basis ($40 quart vs $60 or more). Things like that make me smile. The smile broadened when I discovered an absolutely clean filter in the funnel after pouring through the Desert Varnish.


After diluting the stock solution 20% with water and shaking the mixing bottle the spray-ready coating fluid slid down the sides leaving no residue whatsoever. Wunderbar!, as they say in Sweden.


I chose a 10-foot-long giclée for the test... a sign for Vashon Island Imaging's booth at the Vashon Strawberry Festival coming up on July 17th and 18th. It was printed on Epson® matte canvas and would be stretched after coating. I reckoned that if the sign didn't survive the test it was no great loss.

It was more difficult to get a smooth even coating with Desert Varnish than with either Clear Shield or ECO Print Shield. Possibly the temperature had something to do with that... faster drying does affect the 'wet edge' you need to maintain when doing spray applications.


However after five coats there were still problems as you can see in the picture above. The other two products both required only five coats for an even surface. Desert Varnish required nine.


The results on the sign were good even if it did take extra coating, so I moved onto the next piece in line... another 10-footer, this one of a picture called Olympic Mountains Vista. It has primarily dark tones of blue and requires good dmax. We had made an eight-foot version a week earlier and sprayed it with Premier ECO Print Shield gloss coating. It looks just the way it should... sensational... and so would make a great comparison for the MOAB® Desert Shield coating test.

After laying on six coats a weird spray anomaly occurred. I couldn't take a picture of it because it had to be gotten off the print right away as Desert Varnish sets up fast, especially on hot days. After considerable deliberation I determined that it was a prepubescent 'string'... a string that hadn't fully coagulated. That fear was confirmed when I poured the solution in the spray gun back through the filter. You can see the results in the picture below.



I recognized the problem from my days of rolling on coatings of Clear Shield and these are described in detail in the book. Basically what happens is that when you cut the stock solution with water the coating starts setting up in slow motion. You have to use the working solution fast to avoid any coagulation resulting from the slow curing in the container. The problem had never occurred before while spraying, probably because the other coating solutions require fewer coats so you are finished before the coagulation gets problematic. But when you have nine coats to deal with, the solution is in the sprayer container for nearly twice as long... long enough for the strings to start forming. You can tell something is wrong if your sprayer spits out even one little bit of crap... that is the tip off, or so I learned. However, I don't expect to be using Desert Varnish after my one remaining pint is used up so the problem shouldn't reoccur. Until then I'll know to filter the working solution more frequently during the spraying process.

The MOAB® coating goes through the sprayer with minimal gunk build-up. ECO Print Shield was the worst in that regard, requiring continually alternating coating with water to keep the tip of the sprayer clean. Desert Varnish behaves like Clear Shield. You get the normal back-spray to peel off the flat part of the gun tip, but no build-up in the spray gun needle seating.


Anything sprayed through a gun creates a 'back spray' that builds up on the flat portion of the shooting tip. You can see that I have scratched some away in the picture above. This needs to be removed frequently. While the coating is still wet it is easy to clean off the tip with a cotton swab 'Q-Tip®' wet with water. After it is dry you can peel it off with a fingernail.


When you pull back the spray gun trigger the hole in the center of the tip, which seats the flow-control needle, should be absolutely clean as seen in the picture above. To clean out any gunk in the seat hole use a toothpick. For persistent crap use a thin sewing needle. As mentioned, both Desert Varnish and Clear Shield both run clean, whereas ECO Print Shield left so much crap in the needle seating that I almost took the hammer to it.

The problem with Desert Varnish is that you need so much of it that it starts to build up a visible 'haze' over the giclée image (see picture at end of blog). The haze is actually the particulate matter that reduces the gloss of a coating. More particulates means more matte... and less dmax. All 'satin' and 'matte' finish coatings have these particulates but usually you don't need as much thickness so the dmax doesn't suffer as badly as with Desert Varnish. This whole subject and why matte finishes act as they do is fully described in the book.

You can avoid the dmax problems and uneven surfaces by spraying the stuff on really lightly... but protection suffers as a consequence of the thin coating. Since we are a commercial giclée printing shop at Vashon Island Imaging, I want the coating we use to be as bullet proof as possible... they have to at least stand the Windex® test, which is a wipe down with a Windex® drenched paper towel or a wipe with a wet sponge. If you can do that to your giclée the coating is thick enough.


Curling edges are another way to tell if the thickness is sufficient. As the liquid laminate coatings cure they shrink. Because the shrinkage is on only one side of the giclée, curl happens.


You can see in the picture above that the giclée of Olympic Mountains Vista coated with Desert Varnish (right) has suffered much more dmax loss than the same picture coated with Premier ECO Print Shield gloss coating (left). The Desert Varnish coated print will need to get re-coated with a good clear gloss coating to try to restore some dmax and contrast by eliminating the scatter light caused by the MOAB coating... for which we'll be using Clear Shield.

In fairness to the MOAB® product, it looks just fine on light-toned pictures and 'normal' ones. However, Desert Varnish is inappropriate for any work that requires good dmax. The fact that there is only one kind limits the use. With the competitors products you seal the giclée with gloss and then adjust the surface using either satin or matte or both in varying degrees. But with Desert Varnish no such tweaking is possible.

Cost wise Desert Varnish turned out to be more expensive than its competitors, because of all the extra coating you have to use to get an even looking surface. The two 10-foot by 17-inch giclées tested used up just under a quart. That means that $40 in product covered roughly 30 square feet... for a cost of $1.33 per square foot. That compares with about 60¢ per foot for Clear Shield and Premier ECO Print Shield, making Desert Varnish twice as costly to use. I don't mind paying twice as much when the results are too... but two times the cost for one-half the quality? I don't think so.

Legion Paper® has built a slick website for their MOAB® products, including Desert Sjield. They have plenty of blogs and other programs about how to print. My hat's off to Andy Biggs and the efforts of all those at the company who support education as I do here at Vashon Island Imaging. However, a slick website doesn't gloss over a dull product.