What is the best way to season a cast-iron skillet? There is no question more divisive in the world of cast iron cookware. Everyone has their tricks and their tools to build a nice foundation of seasoning, but no one can seem to agree on the best method, much less the best oil. So we asked four people who know more about cast-iron skillets than your average internet commenter: Isaac Morton of Smithey Ironware, Dennis Powell of Butter Pat Industries, Liz Seru of Borough Furnace, Stephen Muscarella of Field Company and Stuart Shank of Stargazer Cast Iron. Here’s what they had to say.

The Best: Grapeseed Oil

Every expert praised grapeseed oil. Stuart Shank of Stargazer Cast Iron says its strength comes from a high smoke point and low saturated fat content, which make for a “slick, durable seasoning.” Smithey Ironware’s Isaac Morton, meanwhile, likes its neutral odor, and he uses it to season every pan he sells. Stephen Muscarella of Field Company asked himself what oils would be useful in applications other than seasoning, are relatively easy to obtain and carry a neutral odor and taste. This led him to grapeseed.

“We like organic, cold-pressed oils for environmental and health reasons, and the chemistry is clear that oils high in polyunsaturated fats are the best at crosslinking into a durable coating,” Muscarella said. Another highlight: it’s affordable.

Good: Butter and Animal Fats

While grapeseed oil is great, Dennis Powell of Butter Pat Industries prefers the classics: saturated fats like butter and animal fats, which season your pan naturally during the cooking process. The benefits of doing it this way should be obvious: you don’t have to buy a special oil for seasoning and you don’t need to apply dozens of layers of seasoning. The downside is your pan won’t have the best-looking seasoning (expect some streaks and dark spots) and it may be slightly uneven. But once you’ve seasoned this way enough times the whole pan will turn black anyway.

Also Good: Flaxseed Oil

Flaxseed oil is an odd choice, but a popular one among some cast iron experts like Liz Seru of Borough Furnace. It has a very low smoke point — the temperature at which oil begins to polymerize to the pan — but it’s also one of very few food-safe “drying” oils, meaning it dries out naturally. The main drawbacks are price, smell and precision. Compared to common cooking oils, flaxseed oil is expensive and typically only found in pharmacies and health food stores. There are also many examples around the web of flaxseed oil being a bit finicky, with some testers reporting long-term durability issues. And it smells pretty bad.

Bad: Olive Oil

No expert recommended America’s most popular cooking oil. “Olive oil is tougher because its smoke point is usually so low,” Morton says. In other words, every time you heat than pan up near or above its smoke point, the seasoning can begin to degrade if it’s not perfectly adhered.