Material for infilling on metal

First post here and I hope I’m getting this to the right audience. Obviously, I need suggestions for a good infill product for filling stamping and engraving on metal. This metal will already have a finish applied that I do not wish to remove or harm and there are a variety of parts and a variety of finishes already applied.

My project is this; I am filling the numbers and letters in various places on several different firearms. The primary application is to highlight the numbers on a magazine so that you can read the remaining rounds numbers in a low light situation but I would also like to fill numbers, letters and in some cases designs purely for aesthetics.

I have watched a number of videos on the subject but would like input from anyone with any experience in infilling similar to this before proceeding. I want subject easy to work, but with more wear resistance than wax crayons and as I am completely devoid of any type of artistic skills, something easier to apply than freehand application of hobby paint with a small brush is an absolute requirement.

Anyone that can offer any suggestions please know your input will be greatly appreciated.

I just used Pebeo Vitreo 160 glass/metal paint on metal this past weekend. I didn’t use it for infill, but it is fairly thick. I’d think you could wipe some over and then wipe off the outside. It’s water-based and takes 24 hours to dry. After it dries, it can optionally be baked at 160⁰C / 320⁰F for 40 minutes if your part can stand being baked, in order to make it tougher. But for finishes that could be damaged by heat, baking is supposed to be optional.

1 Like

Don’t know if this is applicable for your application.

I use various materials for infill.
This one is animal bone [get chewing bones from pet store they are already dry]
I grind chips of them in a coffee bean grinder and fill, in this case a brass tube. Then saturate with thin CA glue followed by accelerator. Grind/sand to finish.

Other fill materials include ground coffee and various fills you can find a Michaels.

thanks for the info! This sounds quite promising and something I will probably try.

Question for @mcdanlj or any other reader, Do you have any experience with their Glass Paint Outliner? In some of my applications the thicker consistency might be useful if it is indeed much thicker than the regular product.

I love this idea and the outside the box sourcing for material! While this wouldn’t work for my current project it is without a doubt something I will keep in mind or future projects. I can think of two right off that would probably be a good match with this method.


I referred to what I need to accomplish as infilling but that might not be the best match for a name of what I need to do. The depressions I need to fill are only in the few thousands of a inch deep range and are something easily filled by a fairly thin liquid but a smooth paste or cream would also potentially do a good job, with the right product of course. None of what I at filling is located on parts exposed to high heat. Nothing above a warm to the touch temperature range so high heat durability is not a requirement.

I have experience with exactly one of their products, used only once:

The black went on a deep gray, and dried to a glossy black. It was fairly viscous, enough that it held brush marks. About as viscous as acrylic art paint. That’s all I know!

As luck would have it, that is the product I was asking about! They way you describe it sounds like it might do the job. If it’s too thick I could probably thin it very slightly. Worth a try if no better sounding options are presented. Thank again for your help and thanks again to @donkjr, I can’t wait to try that with my very next project, handles for a cutting board.

I think they also sell a thinner. Not sure, I was looking at a lot of different paints for my project (really one of my children’s project, but I provided the research and $$).

LOL How many of “my” projects over the years have that same exact back story? Both of my kids are now to the point that almost none of their projects end up on dads bench, but occasionally I still provide some work in the way of having questions bounced off me. Which I enjoy immensely of course.

This one however, is my own.

1 Like