Is there an ideal width for boards, making a panel 2' x 3'

I need to make a panel close to 2' x 3'. The wood I have is 10" wide, but my jointer is only 8" wide. Is there an ideal width of boards for panels; or just make the widest boards you can to minimize glue lines.

The ideal width is a calculation of a few things.
What you have
What you like working with
What species it is
What you want the look to be
and
What your machines can handle

Unless you're making a reproduction or some type of piece that requires a certain set of parameters, make the panel as you see fit. You may find that many thinner boards gives a better aesthetic than a few wide ones and so on.

That makes sense, I was just concerned that there was a formula to determine ideal size of the boards. There isn't so I can play with what I've got.Great.Thanks for the input.

There shouldn’t be any glue lines.
If you have sharp knives in your jointer and it’s cutting right there shouldn’t be any glue lines. I have a 12 inch wide jointer but prefer smaller widths glued up to make panels.
Good Luck

While I personally prefer wide boards to stay wide boards, there are practical matters when it comes to preparing the material. So in your situation, if the boards really need to flattened on the jointer, then 8" less whatever small amount lets you space the joints evenly. And if you can carefully select your lumber for grain and color, you may be able to make those joints almost completely disappear.

Unless esthetics call for wider panels, I try and keep my boards under 5 inches wide. The greater the number of boards, the less trouble any single board can cause. I think of it as diversying my portfolio.

Since you will have to rip some boards down it makes sense to pay attention to the grain patterns. Try to rip the boards where the grain on the edge of two faces will match when glued up. This is a great way to hide the glue line.

YMMV, but I never maximize for width. The width of my boards are determined first by my own physical limitations or machine limitations, second by stability, and third aesthetics,

Personally, I am partial to rift/qs on panels because it really hides the glue lines. So, I either rip out the center, flat sawn section, or at least make the glue line near the edges of the board where the qs sections would meet.

If there is a wider board with some nice figure in it, I'll put that in the center and put narrower boards on each side.

I remember Sam Maloof saying that he tried to keep the individual boards on a glue-up to a maximum of about 8 inches wide for maximum stability of the glued-up panel. Even though I have a 12 inch jointer, I have always tried to keep my individual boards to 8 inches wide or less.

Yes, wide boards should not be ripped up …without a good reason. Some guys make a big deal about wide boards , and then do bad work
by ripping them up for inappropriate work just to make their work easier. A good reason for ripping boards and re- assembling is to make
beautiful wide boards, and I can do that a lot better than Frankenstein did with his plentiful “material” .

In my shop, the width of boards is dictated by the stock I can get primarily, with few exceptions. My supplier sends good quality stuff, but when I say 400bf of something, s3s, he selects the width that gets on the truck. I don't have the time to go hand pick, and the price would be much higher if I did, so I use what I get. You'll find that waste and cost goes down if you accept that and develop techniques around it.

I like to keep boards as wide as I can. I think it normally looks better, it always wastes less material, and it takes less of my time. Glue up is simpler. I don't think there is a stability reason to reduce board width. Stumpy Nubbs did a video recently which argued against alternating growth rings and recommended just selecting boards by appearance. I select for appearance. I usually don't stain so selecting boards is my only way to color match.

The top of my dining room table is a little over 42 inches wide and 10 feet long. The top is six boards because that is the least I could find in my supply that would give me a 42 inch wide top. It is flat. There is no bread board ends. I has the same finish on the bottom as it has on the top - same number of coats. I think that is important. I have two coffee tables in my GR with cherry tops bigger than the OP's project made the same way as my dining room table. One has three boards in the top and the other has 4. They too are flat.

There is a stability reason to rip boards but only if you are willing to discard or repurpose the flat sawn portion. This pertains most to log-width slabs.

This is even more true when the center part of the board is near the pith.

To make a blanket rule is probably not appropriate. It all depends on the particular board.

I am surrounded by projects made with full width boards arranged for appearance and not for stability. You are all welcome to make your projects as you deem best but I've been doing things my way for about 5 decades now without issue. It is important to use boards that are adequately dry and to finish all sides the same but beyond that, I do not do anything special for stability.