How to fill the crack in this slice of wood with resin?

'Just wondering what you are planning to make with it if you can fill the split?

They are from my daughters wedding, so I was hoping to make some kind of souvenir of that! I am an excellent wood burner too! Do you have any ideas?

In the Japanese art of Kintsugi, the crack is treated as an honored imperfection. Consider gold as a topping for what ever you figure out to fill it.....

You first need to adhere tape to the bottom and side of the split so the resin doesn't ooze out. I've seen people use duct tape for porous surfaces. The side might be trickier with the bark. You can often find pliable modeling clay for silicone mold making that might work best for this. Roll out the clay and flatten it the best you can and raise the base of the wood slice up to keep it level. Stick it down onto the clay and bring the clay up along the bark on the outside giving yourself a bit of a lip at the top. Squish the clay into the bark gently, just enough to give you a seal. You don't want it to stick in and then pull off the bark when you remove it. Mix up your resin as per the instructions and if you want to add colour or gilding like Fou suggested purchase gold mica powder to mix into it. Stir the powder in well but don't mix too vigorously or you will get bubbles. Once mixed without lumps, pour the resin into the crack. Let sit until dry. After the required set time peel off the clay and buff the sides that had the clay attached. Youtube has many videos on how to pour resin into wood pieces.

I've never done it, but apparently, you tape the side and bottom and then fill it with the epoxy resin. Keeping it in a dust free environment is also important!

If you're going to burn in, I'd burn it first, and THEN fill it. That way, you can cover the top too to protect and shine up the burn.

Do not get that you are going to paint slice. If so, could you fill with an autobody filler? Do not know if product can be colored/tinted or could you incorporate a color into your design. Just thinking back to when we sold first home. Contractor used autobody filler to a repair the base frame on outside of front door ruined by lack of water run off after rain/snow. Was painted to match the existing trim. Worked like a charm, passed inspection, none the wiser. Just a thought. Good luck.

Me again . . . Another idea which i like better. Do you have the means to cut a section of another piece of wood to fill the section as closely as possible? You may not match it exactly, but it would be closer then using a lot of product to fill the gap. Also, could make a template to form the edges of filler piece to better fit the gap. I like to birch wood as it is beautiful left "raw," has a nice grain and varnishes/stains beautifully. My opinion.

I have used hot glue and then painted it.