5 Things For Quality Sublimation Printing
Information based on hundreds of prints using a Heatpress Nation 7-in-1 heatpress. These are all quality control and production tips I had to learn the hard way.
Table of Contents
Boundaries and Imprint Area
Keep it Straight
Keep it Clear
Dust and Things
Refine YOUR Process
My Mug-Printing Credentials
About a year into my in-house, hand-printing of mugs for in-person selling and online orders, I’ve printed well over a hundred 15 oz ceramic mugs and / or 20 oz stainless steel tumblers. More importantly, however, is that I’ve had loads of duds. I’ve run into a lot of issues hand-printing, which means I’ve been forced to read, troubleshoot, and fix problems.
There were a few frustrations I ran into that I found weren’t well documented in most of the places I did my research, leading me to having to figure out my own processes / troubleshooting.
Briefly, the process (there are loads of videos with better instructions):
Prepare blank (dust it, make sure it’s dry, remove lids / plastic inserts)
Print design (Canva, download, need sublimation ink, dedicated sublimation ink printer, and sublimation paper)
Tape the design to the blank (need heat resistant tape and butcher paper)
Set the pressure (not applicable to all heat presses), set the temperature, and set the timer. This will differ from heat press to heat press. Review documentation of the blank and / or the heat press. Be prepared to need to run tests to determine this.
Peel (I peel ceramic mugs hot, but stainless steel tumblers cool)
Quality control
Hardware and software notes:
Canva Pro for the designing. I download at 3x for optimal image size and transparent background. I usually take my designs, resize them in Canva and arrange in an 8x10 inch project, which I then download as my “print file”.
Sometimes I use GIMP to mirror my design horizontally, but I found printing (Mac OS, GIMP, and Epson sublimation printer) was tricky. My designs would come out a little smaller or a little bigger than expected. Something to do with the “inches” to “pixels” transformation. I didn’t care for the inconsistency, so I stopped using GIMP.
I print using Preview (Mac OS app). I’m sure to set my print to 100% scale (sometimes it resizes; really depends on the printer drivers I think). The color profile / image quality comes out exactly the same, to my naked eyes, as GIMP, but with more size consistency and less random resizing I can’t control.
I use the EPSON ET-2800 which works nicely. Every once in a while I’ll get a rogue dot of ink, but I can usually just cut it off and move on. I use Hiipoo Sublimation ink and A-Sub sublimation paper. The butcher paper is generic from Amazon.
My blanks are 15 oz ORCA coated ceramic mugs. I have sourced them from Heatpress Nation and a company called RPL. Both seem to have similar quality. Be sure to consider any insurance needs for shipping. It seems unavoidable that some break in transit.
I get my 20 oz stainless steel tumblers from Alibaba Express. I prefer to include a plastic straw and the rubber-grippy option to stick on. ORCA coated versions are available, but I myself haven’t used them.
My heat press is this one from Heatpress Nation. I find it has limitations in the imprint area, most noticeably on the 15 oz ceramic mugs. But overall I like it.
The 5 Things - A Checklist
Boundaries and Imprint Area
I watched a lot of videos and read several blogs, but I’ll have to tell you, it took me an embarrassingly long time, and several mugs, to figure out the imprint area matters and aren’t necessarily as documented.
I use the 15 oz ceramic ORCA coated blanks from Heatpress Nation (I highly recommend these mug blanks). They have a large C-handle for a nice comfy hand-feel. They’re sturdy, well made, and dishwasher safe. They hold the prints well and once I determined my modified imprint area, I rarely run into heat-related transfer issues.
For this mug, the dimensions for the imprint area does NOT go from handle to handle. Handles, and the bottoms, of mugs act as heat sinks. Specifically, as well, the Heatpress Nation 7-in-1 Heat Press does not work handle-to-handle. Doing some math, the indication is to keep the ink at least ~0.7 inches away from the handles on both sides to ensure a consistent transfer.
I’ve found through trial and error, and duds, and frustration, I like to keep my designs and images about 1 inch from the handles. This gives me the cleanest heat transfer for the edges of my designs. This might differ with a different combination of blanks and heat press.
The first step to my mug printing is going through all my blanks, using a tailor’s measuring tape to measure 1 inch from my handle on both sides, and placing a piece of heat resistant tape as visual marker and reminder of my boundary.
A few things to note:
Using the HPN 7-in-1 with the clam shell like heating element, it is possible to break a handle off the mug. It’s quite startling. Be careful, before closing down the heat press, to keep the handle as centered as possible and away from the metal edges that close down.
There’s a need to design around this limitation. Meaning, I won’t offer or sell any design that requires edge-to-edge, or bleeding prints. My designs have variable edges and transparent / white backgrounds as I find this has more flexibility for small errors. For example, I would never do a traditional “photo mug” because that would require perfectly straight and crisp edges from handle-to-handle, top-to-bottom printing.
Imprint areas are a combination of blank AND heat press. In my experience, while the documentation indicates I can get closer to the handle, my blanks in my heat press don’t usually turn out that way. The best way to determine the “real” imprint area with your combination of blanks and heat press is through, unfortunately, trial and error. You can use documentation and blogs to help narrow things down, but run a systematic test (see below) in order to document your own processes.
Keep it Straight
Seems obvious and is stated in most Youtube videos: “make sure your image is straight and centered!” For whatever reasons, this is the result of the majority of my duds. I really have a hard time quality controlling the actual image placement on a mug. This is, in my opinion, one of the most important things to jig. My jig is not at all scalable, and one of the reasons I chose to stop hand-printing as a main source of revenue for my business.
The nice thing about the 15 oz mugs I use is there is a circular rim on the bottom of the mug that is pretty uniform. I’m able to use my tailor’s measuring tape, on the metric side to get to the really small millimeters, to pick a spot in my design and measure.
To do this I chose 2-3 spots that should be level with one another (i.e. if a word has two of the same letter on opposite sides of the design, or the line I have in some of my science designs). I then measure VERY carefully from those spots to the top of the rim of my bottom. I then use that number to also place, measure, and level the design on the second side of my mug.
Notes on this:
If you’re printing a smaller design but on both sides, it is my recommendation to cut them into two separate pieces of sublimation paper. This is because there is a slight concaveness to mugs, typically, even on the very straight-looking 15 oz mugs. This makes alignment and tightness of the wrap almost impossible.
Even the slightest mis-measurement can cause a crooked design. When I measure, I note where I’m placing the measuring tape. Example: If I’m measuring a line from one of my science graphs, I note where the line of the design lands along the line of my measuring tape; whether or not I aligned to the top or the bottom of the lines. This way I’m measuring the same way across the entire design of the mug.
I start on the 2nd cm of my tailor tape to simplify the consistency of which I measure because of the little metal nubby thing on the end.
Keep it Clear
This quality control is important, but there is a little more room for error here as most people genuinely won’t notice what I call “gassiness”.
By “clear”, I mean a few things:
Not gassy. Meaning the lettering / image is crisp with little blur around it. This is usually because the heat was on too long, or the sublimation paper wasn’t taped down enough.
Not streaky. Meaning it’s the same solid crispness throughout. This seems to happen if the sublimation paper isn’t taped down enough OR if I peel a stainless steel tumbler while it’s still hot. I’ve taken to only peeling tumblers cool.
Not missing pieces to the image. This seems to happen from the pressure of the clam shell heat press heating element if the paper isn’t taped down enough, causing pillowing underneath. This tends primarily be an issue with tumblers.
No heat resistant tape remnants / burn marks. I don’t know why this happens, but it happens more with stainless steel tumblers. I prevent this by minimizing the tape having direct contact with the tumbler itself.
Online in the directions for using heat presses they often say to make sure the image is “tight” and “won’t move” when adjusting the blank in the heat press.
Those words are vague and somewhat not useful, which caused me great distress as I created dud after dud of gassy or streaky prints.
15 oz Mugs
To keep my sublimation paper “tight” on 15 oz ceramic mugs, I reduce the amount of blank, extra, sublimation paper. That’s just more paper to control and keep tight. This means if I print an image on both sides of the mug, I print 2 3.5x4ish inch sized pieces and tape them each separately.
I tape down all four sides with a small, 1 inch piece of heat resistant tape. As long as the paper doesn’t have any gap between it and the blank mug, it seems to remain tight enough.
I don’t move my mug once the clamshell is completely shut. I do any adjustments gently as I close it down to ensure the handle is centered.
I find I can peel these whenever I want, hot or cold.
20 oz Stainless Steel Tumblers (generic version)
To keep my sublimation paper “tight” on a stainless steel tumbler, I tape initially at the top of one corner, sure to keep paper between my tape and the white coating of the tumbler. I fold the tape over to the inside.
I pull tight. As tight as I can. Overlap the edges of the paper so the tumbler is completely wrapped. Tape down the seam all of the way to the bottom.
I do NOT tape around the tops and bottoms. I find the extra pressure on the paper can create weird air pillows inside that might not be noticeable but they will create streaks, weird blank spots where the clamshell closes, or gassiness.
I let my tumblers cool to the touch before peeling.
Dust and Things
Dust can be found in the heating element or on the blank itself. I find this to particularly be a problem on my 15 oz ceramic mugs. I used to ignore this step, but had a few duds from it, and decided it’s worth the extra minute or so. Internet suggests using a lint roller. I found that sometimes left weird residue on my mugs which makes me nervous. I use a microfiber cloth to clean off my blanks before taping the design on. Don’t use water. Moisture will cause streakiness in the print.
I did have a mysterious red dust that would appear, often after I printed, all embedded in my coatings, that I couldn’t for the life of me figure out. Eventually I realized it was the hot pad I was using to let my mugs cool. Be aware of all the lint possibilities! There could be many.
The butcher’s paper, or sacrificial paper as they call it on some sites, will help protect your mug from any dust that might be on the heating element. I don’t stress about that much. I also save my butcher’s paper and reuse it if it’s still in okay shape after a print.
Refine YOUR Process
I recommend running systematic testing based on each blank and each heat press combination. Write yourself notes. Create your own checklist.
Choose a design to run your test on. I recommend choosing one with a good array of colors so you can see how that’ll turn out as well. I do NOT recommend using a custom design order as your test.
If you decide to test using different color profiles (I use the default in GIMP or in Preview from my Mac; other printers use custom profiles based on the ink / printer they’re using) label them right on the design itself. I have a test mug with color wheels I downloaded that also say “GIMP default” and the name of the other profile. So now when I look at my test mug, I don’t have to remember which one was which.
Choose the setting you’d like to test. On my heating element I have pressure knobs that need to be adjusted, temperature to set, and a timer. Systematically choose the variations of those settings, write them down, test them, and notate results.
Test boundaries of imprint area with a solid rectangle of color. I did this over a previously printed on mug that was such a dud there was no saving it (not donate-able or sellable in any way). I printed out a large rectangle that should have printed edge-to-edge and handle-to-handle. I was then able to find the general measurements of where it became clear along the edges and create my own “imprint area” based on the combination of my print and my press. This was really only necessary on my 15 oz ceramic mugs due to the heat sinks of the bottoms and handles.
Once you picked your favorite, if the mugs are in decent enough shape, even if they’re not “perfect”, can you sell them and recuperate costs? Or donate them?
Write it down. Write it down. Seriously, though, write it down. Trust me. You will not remember.
Conclusion
Mug printing was a crucial part of my business, and when they turn out and I ship them off, I am proud and genuinely amazed an idea I had could be manifested onto a piece of drinkware someone enjoyed enough to pay me for and then use, presumably, in their day-to-day life. I also find funny mugs to be one of the best things. When I’m having a rough day, or when I’d be in all day meetings just wanting not be, having a mug with a funny saying or a silly image just makes it all a tad bit easier to deal with.
I like designing them. I like when people laugh and relate to them. I like making them.
I also found the process to not be quite as straight forward as some of the instructional videos make it look. It’s my hope folks learn from my mistakes and duds, and can save themselves some of the frustration I faced.
As of Fall 2023, I outsourced my mug fulfillment to Zazzle (check out my store!) and only hand-print for specialty bundles I sell on Etsy or specialty in-person shows requiring hand-made goods. It’s a nice balance. I can scale and sell more through Zazzle, but still maintain a hand-printed business on an as-needed basis to supplement a bit.
