With Christmas around the corner, I wanted to share this idea, in case you (like me) want to combine your passion for 3D printing with the need to send holiday greetings to your friends and family. Let’s send them a 3D-printed Christmas cards this year! I love sending physical post to my friends – postcards from my travels, little greetings to those I don’t get to see often – it always cheers people up when they get mail! And I thought, “Could postcards be 3D-printed and would they actually be delivered?” Yes, they could. And people love them!
You can download our Christmas card designs on Printables or use them for inspiration and create your own.
Decorations in this photo: Christmas Sack Vase by Decorartor and Prusa llamas.
The Christmas cards are designed in PrusaSlicer and, although they’re multicolor, they can be printed on a single-extruder printer. We use a few tricks and readily available online resources, and in this article we share them with you. Although the designs you see throughout this article are available on Printables, we would like to encourage you to create your own. Read on to learn how.
To prove it works, we sent some postcards to ourselves already.
They arrived within standard delivery times, both in the Czech Republic and to the USA. It works best with the sticker postal stamp, but even the old-timey lickable one sticks to it well. The post office also managed to stamp them successfully, and no card was broken during shipping. The best part is the designs can be your own, personalized, and cooler than anything you’d find in a store.
Postcards printed on Prusa CORE One. Prusa3D sticker was added instead of a signature.
The models are meant to be printed in two to four different colors on any 3D printer – you don’t need any multicolor or multi-material properties. The color change will be done manually, by you. Therefore, we’d recommend limiting the amount of colors to a maximum of four, because more colors mean more color changes and it becomes a chore. We mainly used a Prusa MK4S, because of its easy access to the Nextruder, but the CORE One family printers work equally well. If you have a Prusa XL or a printer with an MMU, you can make it easier for yourself and leave the color changes to the machine.
Say it with a postcard
The postcard works just like any old paper postcard – there is a field for the address, a field for the message, and there are pictures on the other side. We take advantage of the Add shape function in PrusaSlicer, and the Text and SVG modifiers. The SVG icons come from SVG repo, and the Christmas fonts from dafont.com. PrusaSlicer automatically includes any font installed on your computer.
The colors and even the materials are up to you, but PLA offers the widest color variety. Just always stick to keeping the side with the address light colored, so that if the post needs to print something on it, it will be visible. All PLA-based materials combine well, so if you need a shade of brown, you can include Woodfill or rPLA (such as Corn or Algae). And if you need gold or silver, use a PLA blend.
These postcards employ SVG modifiers, Text modifiers using Christmas fonts, and even this font that uses pictures instead of letters.
Include a family picture
Another way to create a postcard is to use an actual photo. Luckily, photos are easily 3D-printable if you turn them into lithophanes. We used this webpage by 3DP rocks to create the lithophanes. Any Christmas-themed picture turns into a card, especially if you combine it with color change by layer in PrusaSlicer. You can also use a picture of your family, which creates a big wow effect for people who are not that familiar with 3D printing. Such a card will probably bring your grandmother the greatest joy. In the same way, you could create tailored name tags for Christmas gifts this year. You can learn more about lithophanes in our earlier blog article.
Lithophane postcards made from stock photos from pexels, and a family picture (AI generated). Use any of your own photos and experiment with manual color change.
To make the card more personal, it is nice to include a note. When adding 3D-printed text, choose from Sans Serif fonts and consider making the text bold. Very fine lines are less likely to print successfully. If you want to add a handwritten note, a signature, or print the cards now but address them later, you can write on them using a permanent market.
Print the card including the text, or add handwritten text later using a permanent marker.
Classic Christmas cards, just better
A more classic approach is to send a card that folds in the middle and arrives in an envelope. But you can’t just print a card from PLA and bend it, it would break, right? We tried this out for you and found out it works. When sliced correctly, it can withstand being folded, put inside an envelope, sent, opened, and placed on the kitchen counter or a fireplace mantel. All you need to do, is to use two print layers with perpendicular infill (this is the default setting) in the part where the card folds. Our models are already designed that way.
Even plastic Christmas cards can be folded and placed in an envelope.
When it comes to decorating, the easy approach is to place pictures (SVG modifiers) on the front outer side, and text inside. But the card has twice as many sides, compared to the postcards, which means twice as much space for your creativity. Though, remember, when it comes to design, less is more. And when you rely on a single extruder, each color means a manual filament change.
Admittedly, the spine of the card would break eventually. The glittery filaments are very prone to that. White PLA performs pretty well, and the PLA blends are the most stable. You could increase the stability by making the card thicker, but in our experience it is not worth the extra material and printing time.
The cards are only a few layers thin, so they are always a little translucent.
There is a way to print a more durable fold. You can print the first layers using a flexible material, such as TPU. For the cards above, this is probably an overkill. However, you can use it to create pop-up cards. One layer of natural TPU (white and translucent) with a few layers of firm plastic on top works like a pre-folded paper model. In this case, PETG is the material of choice, because PLA does not adhere to flexible filaments. You can try out this pop-up gift card, that can even hold money. It is quite hacky, but even this multi-material model can be printed on a single-extruder printer with a little tweaking.
The instructions to build this pop-up gift are available on Printables.
Sharing the secret: how to tailor your own Christmas card using PrusaSlicer
The easy way: Edit one of the existing models
When you open one of the model files (3MF), you find that the selected printer is Prusa MK4S HF0.4 nozzle, but there are 2–4 virtual extruders, all with PLA of different colors. The actual colors don’t matter, but they help to visualize your plan. You can change the text and pictures in PrusaSlicer:
- In the object list (right menu) find the SVG modifiers.
- Right click → Edit SVG → the SVG menu opens on the left side.
- In the SVG menu, click on the little triangle under the picture → choose Change file…
- Select an SVG from your computer. Adjust size if needed, but leave the Depth at 0.2 mm.
- In the object list (right menu) find the text modifiers.
- Right click → Edit text → the Emboss menu opens on the left side.
- In the Emboss menu, change the text.
- Adjust the size and font if needed, but leave the Depth at 0.2 mm.
- Slice it.
Actual printing
When you’re happy with the result, send it to your printer. At the points of the color changes, the printer will pause, unload the filament and wait for you to load another one. It will wait infinitely, but it’s better to wait by the printer and change the filament right away. The Sliced Info tells you the estimated printing time and the number of filament changes. The postcards print in around 30–40 minutes, and the folded cards might take up to an hour, depending on the amount of details.
In the preview in PrusaSlicer, inspect the layers using the horizontal slider on the bottom of the widow, and find out the order of the colors. Load the first one to the nozzle and prepare the others next to the printer in the right order before you start the print. Mind that this is a bit of a hacky way for multicolor printing – therefore the printer is a little confused. When you start the print, it will tell you that the loaded material is the wrong type – you can ignore that if you already loaded the correct color.
The file is prepared for the Prusa MK4S HF0.4 nozzle. If you change the printer, make sure to TRANSFER all the preset changes – and we mean ALL of them.
We emphasize this because by default, Slicer does NOT transfer the Custom G-code (as you can see above). But this is the little trick that makes the manual color changes possible. Without it, the printer will print everything in one color. So, make sure to check that checkmark when switching to CORE One or another printer.
The detailed set of instructions on creating your own design from scratch and including lithophanes in your postcards is prepared for you in this article.
Christmas card printing on Prusa MK4S, timelapse recorded by the Buddy3D camera. The shadows are caused by the human toolchanger.
Final tips
Whether you now start designing your own Christmas cards or not, the single-extruder multicolor printing is a neat trick. And you can design many different models directly in PrusaSlicer, using features like embossing text and SVG modifiers. If you want to learn more such tricks, check out our PrusaSlicer Masterclass – Beginner to Advanced course. Or dive deeper into 3D design with the 3D Modeling in Autodesk Fusion. And if you’re getting into a Christmas mood, consider entering this year’s Winter Holidays Decorations contest.
If you felt inspired and you are now looking for the right colors, our festive filaments recommendations are: Prusament Galaxy Green (literally Christmas in the form of filament), Blood Red (richer and darker than Lipstick Red or Galaxy Red), Viva la Bronze (slightly darker than Oh my gold and offers more contrast), and Pristine White for the “paper” parts. One final tip for you, to achieve a nice surface, use a textured print sheet.
Happy Christmas and Merry Printing!
Christmas Jo Prusa and more decorations is waiting for you on Printables.
I've done the ManualMMU technique fairly often because I don't have an MMU but want to fill in recessed text/logos with contrasting colors for signs, enclosures, control panels, etc. I see in the Christmas wreath card example the custom G-Code has the all important "if" statement to avoid an attempted filament change between the purge line and the start of the print. I use {if layer_z > 0} instead of the {if layer_num >= 0} in the example, but both should achieve the same effect.
I would however, suggest adding two arguments to the M600 color change command.
1. I've found, at least on my MK4S, that the default z-height of the M600 color change during the first cm of a print is too close to the bed for my personal ergonomics. I add the Z argument to lift the nozzle higher. Currently Z75 works well for me, but your mileage may vary.
2. By default the M600 will return the nozzle to the previous location right before the color change. Often this will return the nozzle to a location on the model that won't get covered by the new color so it will leave a dot of the new color. Adding the N argument to M600 will have the extruder move to the next location (start location of the new color) after the color change.
I also have been playing with a way to show on the screen using an M177 command. Before starting a print if I have more than 2 colors I create a cheat sheet of the tool number (0 to max) to my intended colors. I usually print through OctoPrint and I have an addon that pops up a notification in OctoPrint for every M177 command so I don't have to worry about missing the message on the printer's screen. (And M177 doesn't seem to work on the printer's screen when using OctoPrint. I don't know if OctoPrint is not sending M177 to the printer or if the printer ignores M177 commands when printing via the serial/USB port.)
Here is what my tool change G-Code looks like:
{if layer_z>0 }
M117 Change to color {next_extruder}
M600 Z75 N; Filament change
{endif}
I also have "Single Extruder Multi Material" set to false, mostly because I didn't know what to do with the extra settings that show up with that flag set to true ("Single extruder MM setup"). I haven't tried it with that flag on so I don't know how or if the workflow is different. An example that I've published of filling in recessed text (demonstrating a simple method to fill recessed text along with my ManualMMU settings) is for the WiFi cover for the MK4:
https://www.printables.com/model/593937-mk4-wifi-cover-color-manual-mmu
With an MMU compatible printer and PETG+PLA you can print-in-place post cards with removable ornaments inside! https://www.thingiverse.com/thing:7077715