Okay, I need to write an article on how to make a resin keychain without bubbles using a lighter. Let me start by outlining the steps. First, I should introduce resin keychains and why bubbles are a problem. Then, list the materials needed. Next, the preparation steps. Maybe talk about measuring the resin, mixing, using the lighter to remove bubbles, pouring into molds, and curing. Wait, the user mentioned using a lighter specifically. So I need to focus on that technique. How exactly does a lighter help? Oh right, the heat from the lighter can pop bubbles on the surface. I should explain that process carefully. Also, safety is important when using a lighter, so maybe include a tip about keeping it away from flammable materials. Let me check the requirements: 600-900 words, natural headings, avoid unsupported claims. Need to make sure each step is clear and factual. Maybe start with an introduction about the popularity of resin crafts, then the problem of bubbles. Then the solution using a lighter. Materials needed: epoxy resin, hardener, lighter, mold, mixing cups, stir sticks, maybe pigments or additives. Should I mention specific types? Probably not, keep it general. For the process, step-by-step: prepare workspace, measure resin and hardener accurately, mix thoroughly, use lighter to eliminate bubbles. Maybe also mention other tips like using a heat gun or torch if available, but the focus is on the lighter. Safety precautions are crucial here. Handling resin can have health risks, so mention gloves, ventilation, and not inhaling fumes. Also, using a lighter safely—flame control, avoiding direct contact with the mold. Troubleshooting: what if bubbles still form? Maybe suggest re-mixing or using a toothpick to pop them. Also, how long to cure? Depends on the resin, so advise following the manufacturer's instructions. Conclusion to summarize the steps and encourage trying the method. Maybe add a note about experimenting with designs once the basics are mastered. I need to make sure each section flows naturally. Use h2 and h3 headings as specified. Avoid markdown, just HTML tags. Let me structure the headings first:

Introduction to Resin Keychains and Bubble Prevention

...

Then

Materials Needed

,

Step-by-Step Guide

with subheadings,

Safety Tips

,

Troubleshooting Common Issues

,

Conclusion

. Wait, the user wants natural headings. Maybe more descriptive. Instead of "Safety Tips," maybe "Safety Precautions When Using a Lighter." Check for unsupported claims: make sure all advice is based on common practices. No need for superlatives. Just factual steps. Also, the article should be around 600-900 words. Let me estimate the length. Each section should have a few paragraphs. Maybe 100 words intro, 100 materials, 300 steps, 100 safety, 100 troubleshooting, 100 conclusion. That adds up to 700. Adjust as needed. Include lists where appropriate, like materials list with ul and li. Maybe in the steps, use ol for the process. But the user said to use h2, h3, p, ul, ol, li, strong, em. So yes, ordered lists for steps. Make sure to explain why using a lighter works—heat causes bubbles to pop. But be cautious with the flame distance to avoid scorching the resin. Also, mention that after curing, you can remove from the mold and add a keyring. Maybe suggest adding small trinkets inside for customization. Check for any missing steps. Did I cover measuring, mixing, pouring, using lighter, curing, demolding? Yes. Now, write each section concisely, keeping paragraphs short for readability. Use strong for important points, em for emphasis if needed. Avoid mentioning AI or any other tools. Just present the information clearly. Make sure the article is original, not copied from other sources. Use your own wording based on general knowledge of resin crafts. Let me start drafting each section with these points in mind. Ensure the keyword "How To Make