Turn a photo Christmas ornament into a printable panel

A lithophane ornament works because light passes through thin plastic and stops in thick plastic. The image you see is a map of thickness, not ink. That is why a dark background can become a solid block and a bright window can become a hole. The generator's job is to turn the photo into a controllable height field; your job is to decide which end of that field should be thin.

Use the invert control to test both interpretations. If the face is bright in the source but you want the face to glow, the face should be thin. If the background is dark and busy, raise the black point so it becomes a quiet border. Check the result at the intended ornament size, not zoomed in on a monitor. A 70 mm ornament has very little room for a crowd.

Choose one face or one clear group, keep the head away from the edge, and remove anything that will turn into a spike at small scale. A Christmas tree, a pet, or a couple works when the silhouette is simple. A group of ten people at a wedding does not. If the photo is horizontal but the ornament is vertical, crop before upload rather than squeezing the whole scene.

The border matters more than it does on a large plaque. A narrow, stable frame gives the panel strength and keeps the backlight from bleeding around the subject. If the source has a cluttered edge, flatten it or crop it. The free preview is the right place to discover that the ornament reads as a bright blob; that is cheaper than discovering it after a batch print.

The exported STL does not include a hole, a loop, a ribbon slot, or a frame. Add the hanging feature in a model editor and check the wall thickness around it. A hole placed too close to the edge can crack during printing or handling. If you want a framed ornament, design the frame as a separate part or join it before slicing.

The same rule applies to names and dates. The workbench does not create lettering. Add text as geometry in a model editor, keep it shallow enough to print, and check that it joins the panel. A photo ornament with a clean face and a simple added name is usually more readable than a panel crowded with decoration.

In December, a failed print is not just a failed print; it is a missed delivery date. Print one small test panel before committing to a batch. Check the light source, the filament, the layer height, and the hanging feature on that test. Then print the batch with the same settings and the same material lot when possible.

The free preview and the paid production bundle answer different questions. The preview answers whether the photo is worth using. The bundle provides the raw-float depth and verified files when the design is approved. Neither one guarantees a specific print result, and neither one knows your printer. Build the schedule around that boundary.