3D Heart Candle with Customizable Embossment

This is a modular, 3D-printed candle mold system designed for clean pours, consistent alignment, and easy demolding. The parts assemble into a rigid mold body, with printed inserts that help keep everything registered while you pour and cool. Great for repeatable heart candles (and for experimenting with different waxes, dyes, and scents).

The "Interchangeable Embossment" models are intended for YOU to customize. You can add an important date, initials, or any simple design you see fit. Using a slicer or CAD software, you can add your desired embossment. It is important that whatever you intend to be embossed on the candle should be inverted on the actual mold component. 

Print settings (important)

• Wall/perimeter count: 4–5 walls

• Infill: >35%

• Layer height - main components: 0.2 mm 

• Layer height - Interchangeable embossment: 0.12-0.16mm 

• Material: PLA works, but ASA is recommended for better heat resistance and durability.

• Supports: None

What you’ll need

• Printed mold parts + m3 screws (optional)

• Clamp - trigger, vice, or any clamp that can compress the two main base halves. Rubber bands may work as well.

• Wax (soy/paraffin/beeswax blend), fragrance, dye (optional)

• Wick

• Mold release (silicone spray or dedicated mold release; I used petroleum jelly, which worked fine)

• A small amount of petroleum jelly or silicone caulk (for seam sealing)

• Pour pot/double boiler + thermometer

Step-by-step: How to mold a candle with this design

1) Print and inspect parts

1. Print all components using 4–5 walls and >35% infill.

2. Clean up edges or any print imperfections

3. Dry-fit the parts once to ensure everything seats fully.

2) Prep the mold (smooth + seal)

1. Lightly sand any obvious stringing or bumps on mating surfaces (optional but helps).

2. Apply a thin coat of mold release to the interior cavity surfaces.

3. Seal the seams:

   • Easiest: rub a tiny amount of petroleum jelly along the mating edges before assembly (good for small seep prevention).

3) Assemble the mold

1. Place the main bottom halves on a flat surface.

2. Install all of the side modules/inserts in their keyed positions. All modules should slide or snap into place. 

3. Insert and tighten screws evenly (does not need to be tight) so the top modules are fixed to the bottom module.

4. Insert the wick holder into the mold module.

4) Install the wick (centered)

1. Thread the wick through the wick channel.

2. Secure the wick at the bottom:

3. Pull the wick taut and secure the top end:

4. Confirm the wick is centered and straight.

5) Melt and prepare wax

1. Melt wax in a double boiler/pour pot.

2. Typical temps (general guidance):

   • Soy: melt ~170–185°F (77–85°C); pour often ~120–150°F (49–66°C) depending on wax

   • Paraffin: melt ~160–180°F (71–82°C); pour hotter than soy in many cases

3. Add dye (optional) and fragrance (if using) at the manufacturer-recommended temperature.

4. Stir gently for 1–2 minutes to avoid air bubbles.

6) Pour the candle

1. Place the assembled mold on a protected, level surface.

2. Pour slowly into the cavity to reduce trapped air.

3. Tap the mold lightly or gently vibrate the table to help bubbles rise.

4. Leave a small headspace at the top if your wax expands/shrinks noticeably.

7) Cool and top-off (important for clean results)

1. Let the candle cool undisturbed until a skin forms and the center begins to sink (common with many waxes).

2. If a sinkhole forms near the wick, reheat a small amount of wax and top-off.

3. Allow a full cure:

   • Many waxes demold in 3–8 hours, but best hardness is often overnight.

8) Demold

1. Remove the clamps and retainers and release the wick.

2. Undo the screws and separate the mold sections slowly.

3. Gently try removing the embossment inserts first. 

4. Second, remove the top three mold components 

5. Third, split the two bottom halves and remove the candle completely from the mold.

6. If it’s stuck: place the mold in the fridge for 10–20 minutes to contract the wax, then try again.

9) Finish

1. Trim wick to ~1/4 in (6 mm).

2. Clean any seam lines with a warm finger, heat gun on low, or gentle buffing.

3. Cure time (for scent throw), especially for soy: 3–14 days depending on wax/fragrance.

Tips for best results

• ASA > PLA if you plan frequent pours or warmer wax temps.

• Use mold release every time for the easiest demolding and longest mold life.

• For leak-free seams: try silicone caulk externally + let cure.