Experimenting with Koala Inkjet Decal Paper: no clearcoat required

[neil_w]

Part1: Background

Self-printed decals have been an ongoing source of frustration for me, despite the fact that I've generally been successful with them. I've mostly fought two problems:

1. Inkjet decals: they look fantastic, but even after clearcoating (which is annoying) I still have problems with ink running at the edges. This is mostly a problem with white-backed decals when the ink goes all the way to the edge.
2. Laser decals: generally the print quality is less on the laser, *plus* I get some weird surface finish effects that take *many* coats of Future to hide. Also, in contrast to the inkjets, I can rarely achieve a true, deep black, which is more a function of the strange matte-mottled finish on the decals rather than the blackness of the toner.

As a bonus, my current inkjet (an HP all-in-one) doesn't seem to do a very good job printing decals, or perhaps I just haven't found the right settings yet.

So: while browsing on Amazon I found this stuff and thought I'd give it a shot: https://www.amazon.com/KOALA-Waterslide-Printers-Coating-Tumbler/dp/B09CTKNRC1/


This stuff claims that no clear-coating is required, and that the ink will not run. Intriguing. I am experimenting with it now, will document my experience here.

 

[tsmith1315]

 

[mh9162013]

I'm all ears!

 

[neil_w]

Part 2: Initial Experiments

My goal was to try these decals out on the Nibiru Interceptor, for which I have a bunch of decals to print on white background, and no running at the edges will be tolerated. My alternative is laser decals.

Annoyingly, the decal paper has no printing on the back, and just gives a warning to print on the "whiter, shinier" side. The Sunnyscopa paper I normally use has printing on the back that says what king of paper it is (clear/white, laser/inkjet), which is nice.

In any case, the first thing I noticed is that, at least with my printer, the colors of the printed output do not closely match what's on-screen. I had to do a bunch of print/check/adjust iterations to get the output to look like I wanted. Maybe this is a printer setting issue (I was following the instructions, using photo paper / normal quality) but it really was quite different. Here's a comparison of source image, laser print, and Koala print:


Here you can see that the laser is pretty faithful to the colors, while there is a very significant color shift on the Koala paper. Again, maybe a printer issue, but I don't recall having this particular problem with the other decal papers I've used... which were usually on a different printer. Too many variables to control here. Of course the camera is another variable; I've brightened up the photograph a bit but not touched the colors, and I would say that the photo looks pretty faithful to the actual decal sheets I'm looking at here.

OK, so the colors are a bit wonky but not necessarily a problem. Next I wanted to try out the paper and test its claim of ink-fastness with no clear coat. I took a spare block of printed paper (not shown above) and applied it to a piece of PVC. I did two pieces one with Micro-sol (left) and one without (right), just to test if the Micro-sol itself might cause a problem:


Well I have to say that indeed, the ink didn't run. The decals behaved pretty well, didn't require an extremely long soak and slide onto the PVC very cleanly. The Micro-sol didn't affect the ink at all. So far so good, seems to live up to its promise.

However, one thing immediately became clear to me: the finish on the Koala decals was very matte... I mean, *extremely* matte. It says it right on the package (no false advertising here) but I didn't grasp the significance until I looked at the paper.


Most of my rockets are finished with gloss, usually Future; so next up I needed to see what I needed to do to get some gloss on these things. That is still in progress, so it may be a few days before my next update.

 

[tsmith1315]

Great report, @neil_w. Thanks for sharing these details!

 

[neil_w]

Interlude: New Printer Test

They just swapped out the old printer at work for a new one... I figured I had to run a quick test on it to see how it compared to the old one:

The results are Not Good. This printer seems to be unable to print solid black or grey without missing some spots here and there. The color is not nearly as rich as the old one. Notice also that the border between the grey and orange is not that good; it looks like there's a very slight bit of white between them. It has the same mottled finish as the old printer, so it doesn't fix that issue.

What this means is that I won't be doing much laser printing of decals in the future. At least, not big solid color stuff, and not on this printer. Maybe I'll still do black-on-white here and there, but it looks like I might be simply forced to figure out a way to make the Koala work for me for this sort of thing.

I suppose I could also go to Kinko's or whatever and see if their printer gets better results. Perhaps I will give that a try sometime. I don't mind paying for the print if it will give me good results. We'll see.

Back to the topic at hand.

 

[jqavins]

Interlude: New Printer Test

They just swapped out the old printer at work for a new one... I figured I had to run a quick test on it to see how it compared to the old one:
View attachment 581288
The results are Not Good. This printer seems to be unable to print solid black or grey without missing some spots here and there. The color is not nearly as rich as the old one. Notice also that the border between the grey and orange is not that good; it looks like there's a very slight bit of white between them. It has the same mottled finish as the old printer, so it doesn't fix that issue.

What this means is that I won't be doing much laser printing of decals in the future. At least, not big solid color stuff, and not on this printer. Maybe I'll still do black-on-white here and there, but it looks like I might be simply forced to figure out a way to make the Koala work for me for this sort of thing.

I suppose I could also go to Kinko's or whatever and see if their printer gets better results. Perhaps I will give that a try sometime. I don't mind paying for the print if it will give me good results. We'll see.

Back to the topic at hand.

It's sad that there are these new problems, since the color is much truer to the source image. One step forward and two steps back. But it is hopeful evidence that the color problem on the first test might indeed be a printer setting issue.

 

[mbeels]

This printer seems to be unable to print solid black or grey without missing some spots here and there.

Curious that (except for one exception) it has problems with black (primarily) and not the orange color.

 

[neil_w]

Curious that (except for one exception) it has problems with black (primarily) and not the orange color.

Could just be an issue with the black toner cartridge. But even without the continuous black issue, quality is not great.

 

[KenECoyote]

However, one thing immediately became clear to me: the finish on the Koala decals was very matte... I mean, *extremely* matte. It says it right on the package (no false advertising here) but I didn't grasp the significance until I looked at the paper.
View attachment 581281

Most of my rockets are finished with gloss, usually Future; so next up I needed to see what I needed to do to get some gloss on these things. That is still in progress, so it may be a few days before my next update.

Before you noted it, I figured that the decal paper would be matte since it needs something for the ink to be absorbed.

I've also found that most (all?) printers I've used usually have issue printing large areas of black. It seems they often aren't designed to lay down so much of one color while also printing very quickly. Black is the color where you notice it the most due to the contrasting white spots (easy fix is a Sharpie marker! ).

Thanks for the well detailed report!

 

[neil_w]

I've also found that most (all?) printers I've used usually have issue printing large areas of black. It seems they often aren't designed to lay down so much of one color while also printing very quickly. Black is the color where you notice it the most due to the contrasting white spots (easy fix is a Sharpie marker! ).


Thanks for the well detailed report!

1) The old laser printer had no such problem, and the inkjet printers I've used likewise do not (they'd have a heck of a time printing photographs otherwise)
2) Sharpies run under clear coat (including Future)
3) More to come.

 

[KenECoyote]

1) The old laser printer had no such problem, and the inkjet printers I've used likewise do not (they'd have a heck of a time printing photographs otherwise)
2) Sharpies run under clear coat (including Future)
3) More to come.

1) Maybe then it's a matter of the ink not adhering?
2) Shouldn't be a problem except for if it's on an edge
3) come on already!

 

[neil_w]

2) Shouldn't be a problem except for if it's on an edge

Why do you say that? The clear coat will dissolve the Sharpie ink and it will start moving around, which you Do Not Want.

If the problem were only in the black areas, you could conceivably touch them up with black paint, although the touch-up will be visible.

Better solution: don't use this printer.

 

[KenECoyote]

Why do you say that? The clear coat will dissolve the Sharpie ink and it will start moving around, which you Do Not Want.

If the problem were only in the black areas, you could conceivably touch them up with black paint, although the touch-up will be visible.

Better solution: don't use this printer.

I Sharpied this one a bunch and did Rusto 2X. No problems at all.

Do you have any pics so I understand the issue?

Edit add: A paint marker may be a safer alternative.

 

[neil_w]

Do you have any pics so I understand the issue?

No. But I can tell you that in the past my Sharpie touch-ups were ruined by Future. Others have posted that spray clear has also messed up Sharpie... if you had good luck with the Rusto 2x clear over Sharpie that's good to know.

 

[KenECoyote]

No. But I can tell you that in the past my Sharpie touch-ups were ruined by Future. Others have posted that spray clear has also messed up Sharpie... if you had good luck with the Rusto 2x clear over Sharpie that's good to know.

Actually much better to know that there can be an issue that may ruin the paint job, so I'll save the Sharpies for marking my rocket... boxes.

Thanks Neil!

 

[neil_w]

If I get an appropriate opportunity, I'll do some more experimenting and report (probably in a separate thread).

 

[jqavins]

I Sharpied this one a bunch and did Rusto 2X. No problems at all.

Do you have any pics so I understand the issue?

Edit add: A paint marker may be a safer alternative.

If a little dot of sharpie is used to touch up a monochrome field, and it runs when clear is sprayed, it should only run onto the field of the same color. I suspect that's why it for you, and why it might work for the white spots in Neil's black fields. But it's very unlikely to work for the white stripe between the black field and the orange without running onto the orange (I think).

Therefore:

Better solution: don't use this printer.

 

[BABAR]

2) Sharpies run under clear coat (including Future)

Apologize for non-attribution, I can't remember who said this (which is sad for me, cause it was recent, might have been @bad_idea ), was saying that the Scrap Booking folks apparently make no-run black markers that might be helpful, I think he (or whoever) said he used it for the edges of black ink on white paper.

thanks out to @neil_w for tracking this down.

attributes to @Bravo52 here post 99

https://www.rocketryforum.com/threa...-of-the-day-thread.177679/page-4#post-2428689

 

[BABAR]

Won't work on everything, but on the the black on silver star thingies (cockpits?) and maybe the I-shaped things, multitasking might be the answer. Paint or use non-running ink to make solid jet black paper decals that you cut out (and edge with a black non-sharpie pen.) Cut and place over the previous decals. It will give you a 3D effect (very flat greebles?) Yeah, it will take some time, but you've been complaining this build has gone too fast anyway

 

[bad_idea]

Apologize for non-attribution, I can't remember who said this (which is sad for me, cause it was recent, might have been @bad_idea ), was saying that the Scrap Booking folks apparently make no-run black markers that might be helpful, I think he (or whoever) said he used it for the edges of black ink on white paper.

Wasn't me, but I'm glad to learn this too.

 

[neil_w]

Apologize for non-attribution, I can't remember who said this (which is sad for me, cause it was recent, might have been @bad_idea ), was saying that the Scrap Booking folks apparently make no-run black markers that might be helpful, I think he (or whoever) said he used it for the edges of black ink on white paper.

Maybe this from @Bravo52? https://www.rocketryforum.com/threads/tips-and-technique-of-the-day-thread.177679/post-2428689

It is intriguing but the tip doesn't really say anything about whether the ink will run under Future or spray clear-coat, though.

 

[neil_w]

Part 3: Clear Coating

First thing I tried was what I usually do with my laser decals: apply Future with a Q-tip. Here it is after the first coat:

That is obviously horrible. Here it is after 3 coats:

Still horrible. After coat #6, it looked OK (still not perfect, probably could use another coat or two):

I am not interested in committing to 6 coats of Future. I've done it in the past but it kind of sucks. As a reminder, here's a picture that shows the mottled finish of the printed laser decals:

It takes many coats of Future to gloss over this as well. So I thought I should try spray-coating the decal sheets, purely to provide a better surface to apply Future to later on (so I can get by with, say, one or two coats at most). I did two light coats and it came out a bit pebbly. My clear-coat spray technique is very rusty.

From a reasonable distance it didn't look too bad, but I thought it deserved a third coat. I thought it went on really well, but when I inspected it later I saw a lot of this (click to zoom in):

It looks like bubbles in the clearcoat. I don't think I saw this immediately after spraying, and I have no idea what caused it. But I'm pretty sure I can't blame it on the Koala paper. Fortunately I included one extra of each decal, and through some miracle it seems like no more than one of each decal got "bubbled", so I should have enough good ones to do the whole rocket, if I don't ruin any along the way.

The important point here is that after a "normal" amount of clear-coat spray it glossed up nicely. And so, even though it doesn't need the clear-coat to avoid running, IMHO it needs it for gloss. If you are a user of spray-clear, you might be able to get away with just clearcoating the whole rocket after decals are on, although it's still possible the decals won't look quite as glossy as the rest of the rocket.

After looking at the "good" laser and Koala decals, I think I'm going to go with the Koala, because the color is what I wanted (not accurate to the source but I had iterated until it printed the way I wanted.) Some of these should go on this weekend, will report back here.

 

[KenECoyote]

I thought about it some more and I believe that I didn't have issues using the Sharpie because I was applying light coats of clear spray paint which dries quickly. Something like Future stays in a liquid state longer, allowing more time for the Sharpie ink to bleed. YMMV

 

[neil_w]

Part 3, continued: trying again

My can of Krylon clear is almost at the end so I grabbed a can of Rusto 2x Clear Gloss yesterday, and today I decided to try again with the Koala paper. So I printed a new sheet, this time selecting "Matte Specialty Paper". Interestingly, the colors came out closer to "accurate", which (as previously discussed) is both a blessing and a curse in this instance. If I use the Koala paper in the future I will stay with the matte paper setting.

Once again, my clearcoat spray technique (or lack thereof) bit me, and I ruined a few of the decals with.... I don't know, maybe a single run across the sheet that was too slow or too close. It left bubbles which, when popped, stayed visible as rings. Once again, I think there are enough good ones left that I could decal the rocket, but I decided to just use the previous batch, as the clear is more uniformly glossy. I might try, after a few days, putting another layer of clear on the new sheet and see if I can even it out a bit.

Not having to deal with this crap is why I was growing fond of laser decals, despite their difficulties. Oh well.

Here is a comparison of the previous Koala print (left) vs. the new one (right). After clear-coating the colors look a bit closer to each other, but you can still see clearly that the new print is lighter and more orangey than the old. You can't see the bubble-imperfections in this straight-on image.

 

[Bill S]

Have you tried Krylon UV Resistant Acrylic clear coat yet? Its "glossy", but maybe not as glossy as you'd like. I use 4 coats on my decals.

https://www.krylon.com/en/products/clear-coatings/uv-resistant-clear-coating

 

[neil_w]

Part 4: More Craziness

I took a closer look at the original print (with Krylon UV-Resistant Clear) and saw that the black has bled a bit into the adjacent orange areas, yielding a less-than-sharp border:


By contrast, the new print (with Rusto 2x Clear) remained sharp:


Interestingly, the bleeding occurred only with the black ink. The gray/orange borders are sharp and clean.

This is not bad enough for me to abandon the first printout, but it is disappointing. Is it specifically a reaction to the Kryon clear? I really don't know, but the fact that the Rusto did not cause it certainly suggests that might be the case.

 

[neil_w]

Have you tried Krylon UV Resistant Acrylic clear coat yet? Its "glossy", but maybe not as glossy as you'd like. I use 4 coats on my decals.

https://www.krylon.com/en/products/clear-coatings/uv-resistant-clear-coating

That's exactly what I used.

 

[KenECoyote]

Have you tried Krylon UV Resistant Acrylic clear coat yet? Its "glossy", but maybe not as glossy as you'd like. I use 4 coats on my decals.

https://www.krylon.com/en/products/clear-coatings/uv-resistant-clear-coating

That's exactly what I used.

I used to use that for decals as well years back (that was the reco back then ~2015), but I stopped a few years ago for fear that the Rustoleum I was now using almost exclusively may react badly after I apply a final rusto clear coat over the entire model.

 

[jqavins]

View attachment 581444

That would be a nice soft edge effect, if only you wanted that.