Before you upload
The upload guide.
We're building a full design studio inside the app. Until then, prepping your image takes about two minutes and makes a huge difference in how your coaster turns out. Here's what works.
The quick version.
Upload a square image with a solid background, your logo or subject centered, and no more than four distinct colors. That's it. Everything below is the detail.
What makes a good image.
Square aspect ratio.
We print round coasters, and we fit the circle inside a square. Rectangles get padded with a solid color to make them square, which sometimes looks weird. Squares don't have this problem.
Solid background.
A single flat color behind your subject. White, black, cream, navy — whatever color you want around the edge of your coaster. If your logo is on a gradient, photo, or textured background, the result gets muddy.
Centered subject.
Put your logo or subject in the middle with clean space around it. We auto-center what you upload, but starting centered is more reliable.
Four distinct colors maximum.
Our printers use four filament slots. If your image has more than four clearly different colors, we'll merge the closest ones — which sometimes loses important detail. Stay at four or fewer if you can.
High contrast between colors.
Similar colors (two shades of blue, cream and white) can get merged during processing. Use colors that are clearly different from each other.
Minimum feature size.
Text and small details need to be at least 4mm tall on the final coaster. Subtitle text, fine lines, and detailed subtle patterns won't print cleanly at our current resolution. Stick to bold, clear shapes.
At least 1024x1024 pixels.
Higher is fine, we'll resize. Lower than 1024 and edges get fuzzy.
File formats we accept.
PNG, JPG, and WebP all work. PNGs with transparent backgrounds get treated as if the transparent area is the background color you most want — so a transparent PNG of your logo with no background works well.
What doesn't work yet.
These limitations are honest. We're working on fixing all of them.
- Photos with gradients (skies, sunsets, gradient backgrounds). They process into abstract stylized versions that are fun but hard to predict.
- Text smaller than 4mm on the final coaster. Physics problem, not software — our nozzles can't print that small cleanly.
- More than four distinct colors. Bambu hardware limit.
- Non-square images without pre-cropping. Padding adds visible borders.
- Logos that depend on transparency for their design (logos with dropout effects, etc.). We treat transparent areas as a single background color.
What DOES work, surprisingly.
Photos of people, pets, or scenes run through our pipeline turn into Warhol-style stylized art. Not photo-realistic, but genuinely cool. If you have a fun family photo, a pet, or a memorable moment, try uploading it — you might be surprised. We're calling these “Warhol coasters” and they've been the most unexpected hit of the project.
The fastest way to prep your image.
Open Canva (free). Create a custom 1024x1024 square. Drop your logo in the middle. Pick a background color from our palette:
Export as PNG. Upload to us. Done.