Nothing to Disclose
I've had a lot of people ask me questions about turning lip tars into lip pencils and I've answered most of them in this FAQ. However I hadn't covered the issue of metallic lip tars mainly because I didn't own any at the time. Now that I own one (Black Metal Dahlia) meant for wearing opaquely on the lips, I thought I would tackle the issue of the outcome of turning your metallic lip tars into lip pencils.
After turning Black Metal Dahlia into a lip pencil in addition to seeing Phyrra's swatch of her metallic Super NSFW and Batty+Tarred Lip Pencils, I would NOT recommend turning your metallic lip tars into pencils. When I was using Black Metal Dahlia with a brush, I noticed that the lip tar wasn't as watery like my regular lip tars and I had to use more than usual in order to get opaque coverage on my lips. That's because the lip tar is packed full of shimmer and sparkle which makes the base color less pigmented. Some of the other metallic lip tars are also pretty sheer which means they'll be even less pigmented as a pencil.
Using the ratio of 2 grams of lip tar to 3 grams of eyeliner base won't work since the 2 grams of metallic lip tar in a pencil will be more diluted than an equal amount of the regular lip tar. When I followed my original ratio, the color was weaker AND the sparkle seemed very dull. The color didn't seem as "glowing" and "lit from within" the way it was when I applied the lip tar normally.
Here is a swatch of Black Metal Dahlia applied regularly on the top lip and as a pencil on the bottom lip so you can see what I mean. The pigmentation of the pencil is quite poor compared to the lip tar applied normally.
Although you could certainly increase the ratio of the lip tar in your formula, I am a little worried about it impacting the texture and compromising the wear time. I also think that at a certain point you're just diluting the lip tar way too much in an effort to be convenient and I think it's better off staying in liquid form.
In the long run, I'd say apply your metallic lip tars with a brush and save the penciling process for your regular lip tars. I don't own a Stained Gloss lip tar so when I do get my hands on one, I'll be sure to write another post on it!
I hope this post helped!