These are stackable heart coasters with exposed infill created by a couple slicer modifier blocks. Project profiles with these modifier blocks are included for PrusaSlicer and Cura, enabling easy print setup. They are setup for a printer with origin at the center, so you may have to move the objects if your printer has the origin elsewhere. 
 

LOAD ONE of the 3MF project files, NOT the example gyroid infill model or the solid heart model. They're included for viewing only. If you use a different slicer, you will have to load the solid heart STL model and add your own modifier blocks.

These look just fine printed in a single color, but if you want, you can change the filament after the bottom layers are printed to get two-color prints like in the images.

The lower modifier block controls the infill pattern and density with zero top layers. The upper block creates the cavity with zero infill, zero bottom layers, and zero top layers. Both blocks should be configured with a matching number of perimeters, with the default of 3 providing sufficient strength.

The specific heights of the model and the modifier blocks were designed for an initial layer height of 0.2 mm and layer height of 0.12 mm. These settings were chosen to produce reasonably smooth outer walls, given that they are angled and would create a staircase effect. You may have to adjust the Z locations and heights of the modifier blocks if printing with different layer heights.

Note that I have printed these models and can confirm stackability and stength, but the images were rendered in Blender from OBJ format files created by PrusaSlicer from G-Code toolpaths.
 

Other Valentine Models

I have several Valentine models available to download. Go see them on my models page, or click a link below to go directly to a model:

• BE MINE VALENTINE 3D Ambigram
• 3D Ambigram with a Nice Side and a Naughty Side (NSFW)
• I LOVE YOU FOREVER *********(censored) Ambigram
• Love Heart Cookie Cutter
• Customizable Name Heart Cookie Cutter
• Customizable Two Names Heart Key Fob
• Customizable Name Heart Key Fob 
   

The soda can was modified from "Diet Soda" (https://skfb.ly/6RBSt) by Blender3D and is licensed under Creative Commons Attribution (http://creativecommons.org/licenses/by/4.0/).