canned tomatoes

I would advise not to remove the seeds. It may make the sauce slightly more watery, meaning you have to cook it down a little more, but there is flavor (and texture) in those seeds. Not to mention the blood, sweat, and tears that went into growing those tomatoes! Every time I reflect on my own tomato patch and the struggle of getting to harvest, I shudder at the thought of throwing any of it away.

For a basic tomato sauce, you don't have to remove the seeds and I personally wouldn't in the interest of keeping things simple. But it's just a preference. There are some recipes calling for tomato sauce or puree that are better seedless, depending on desired texture and appearance.

Many recipes tell you to scoop out the seeds, but recently I have been reading that the seeds and the gel they sit in are very flavorful. Now I don't bother with that step.