How to paint bright white semi gloss mantle to look like wood?

There are lots of ways to do this, and lots of products to help... I would check out Pinterest to find ideas and how to's (including the products needed) and then Youtube to watch someone do it....Have Fun !!

Just Google search faux painting. There are a number of pages out there that will explain the process. Look at as many as you can until you feel comfortable figuring out what tools to buy and trying it on your own. There is more than one technique and you know they cannot put anything on the internet if it's not true. So watch several and you'll weed out the crackpots.

I would sand it and apply good quality wood veneer. Then you could finish it as you wish : stain, wax, varnish, etc.

I have a post on Hometalk with wood veneer (red oak for this one) : http://www.hometalk.com/diy/living-room/furniture/turning-old-coffee-table-into-memory-32202057

Good luck!

Buy a "wood grain" paint roller. Sold at craft and hobby store and big box home improvement centers. If you leave the white as is and add brown it could look like birch wood.

https://www.etsy.com/listing/257604513/wood-grain-pattern-decorative-patterned?gpla=1&gao=1&&utm_source=google&utm_medium=cpc&utm_campaign=shopping_us_a-craft_supplies_and_tools-other&utm_custom1=318ab963-cc45-47e5-a7ef-a06cbf8dc7da&gclid=Cj0KCQjwprbPBRCHARIsAF_7gDY_trORCnl34YD6U_qXCqow7q12TQ3WQ4G0WLlbdAo2A-ryHH_JG4QaAirVEALw_wcB

https://thegadgetflow.com/portfolio/wood-grain-patterned-paint-roller/

At one point I just drug a come over fresh paint in a wavy pattern.