What you need to know about silk printing and label printing

What you need to know about silk printing and label printing
Container and Packaging
by Container and Packaging
September 8, 2020, Updated June 16, 2021

My first job was working in a print shop … I was 10. I silk printed bottles every summer until I graduated from high school. I also walked to school everyday (uphill, both ways, I might add), barefoot, in the snow (when we got snow) and had to use a card catalog full of index cards to find books at the library. My young apprenticeship as a bottle printer taught me many things, one of which I will share with you now: analog and digital printing processes are VERY different.

Read on to learn the benefits and limitations of analog and digital printing and what you can do to ensure your packaging design is picture perfect!

Silk Printing
Silk printing is a form of analog printing (using plates or silk to transfer ink to an object). I wrote a post about the silk printing process in All you need to know about silk printing, check it out. In a nutshell, the basic process is this: ink gets squished through a screen of stretched silk onto your bottle.

Benefits
One of the greatest benefits of silk printing is that you can actually apply the ink directly to the container or lid! I put an exclamation point there, because I think that’s pretty cool. Anytime you can apply art directly to your container, closure, canvas, skateboard, etc, that’s a plus. It gives it legitimacy because it’s fixed, it won’t come off … it’s permanent.

Limitations
Silk printing’s pretty great, but there are limitations. Silk printing is best when restricted to one, maybe two colors. Sometimes we’ll do three colors, but only if you break one of our arms. Read on for why we’re hesitant to do more than two colors.

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Registration marks are indentations on the bottom of many plastic containers

On the bottom of most bottles is a little indentation called a registration mark. (Sometimes there’s one, sometimes there’s two.) These registration marks allow a printer to “lock” the bottle into the print machine so that it can be printed with multiple colors. These registration marks allow you to “register” or line up color one with color two on the bottle. The more colors you have the more challenging it gets to line them up … extremely more challenging.

These registration marks, the locking mechanism, the print machine, the tension of the screen, the ink squishing process, the temperature in the print shop, the ink viscosity, the quantity printed, the humidity in the air, the time of year, and yes, whether or not the printer woke up on the right side of the bed ALL contribute to whether or not color two will line up with color one. There are so many things that CAN go wrong, and DO go wrong, that thinking about it is starting to trigger some negative childhood printing memories that I’ve repressed.

Tips for silk printing success

  • Limit your colors to one or two.
  • Use solid shapes and vector graphics in your artwork (gradients, meshes, shadings, and halftones do NOT work when silk printing, trust me).
  • Use the PANTONE Matching System (PMS) book for exact color matches, this is what the printer uses to mix your ink colors.
  • Create (or have created) artwork without tight registration. Color one and color two can shift 1/16 inch. Please allow for these tolerances.
  • Use a professional designer (like one of our in-house designers at CPSD, I know, shameless plug). They can help you create or edit existing artwork to be optimized for silk printing.

Label Printing
Digital printing is the process of using a computer and digital files to map where ink should be shot. I know, I’ve probably grossly offended digital printers across the galaxy with this over-simplified definition, but essentially, that’s what it boils down to. In the packaging world, and for the intents and purposes of this post, this most often refers to printing on some kind of paper or plastic label that is then applied to the container or lid.

Benefits
The coolest thing about digital printing is that it is infinitely more accurate than silk printing! Because digital printing is more accurate we can go crazy with color (yeah, we print people can throw a wild party)! You can get full color, photography-quality prints on your containers. In most cases, you just have to put it on a label first.

Limitations
Labels are great, but there are some minor drawbacks. Unlike silk printing, you can’t print directly on the container … you have to print on a paper/plastic substrate (a technical term for the material you print on). Occasionally, labels can peel, wrinkle, or run. All of these limitations can be overcome. Some labels are made of plastic, or can be coated with varnishes to protect them from water, refrigerators, even sharks (just kidding on that last one). Labels can have different adhesives that keep your label from peeling, coming off in the shower, or going limp in the fridge.

To DIY or to not DIY
If you want to make sure that your labels don’t peel, don’t come off in the shower, don’t smear when wet, don’t go limp in the fridge, then I STRONGLY recommend that you don’t DIY (Do It Yourself). If you don’t care so much about how your label performs or looks, then yeah, save some money, and go STAPLES and print them at home. CAUTION: They’ll peel, run, come off in the shower, smear, smudge, etc. These types of labels are not intended to hold ink or be stuck to plastic or glass.

Tips for label printing success