How Can I Set One Item to Use Flat Rate Shipping While The Others Don't?

Basically, I run a comic book and collectible online store. Things come in various sizes, shapes and weight. The USPS and UPS modules have worked wonders for my ordinary shipping needs.

Now I have an exclusive t-shirt that I will be selling, which even at it's lowest weight value, still comes in at a relatively high shipping cost. I would like to offer flat shipping for this t-shirt to anywhere in North America, while the rest of my items still should only use the USPS and UPS modules I have set up.

Is it possible to set one item to use something specific and different than the rest of the store?

Thanks in advance for any help.

Fretty
https://www.universal-heros.com

And what should happen if I buy my Spiderman comic and a this T-Shirt in the same order?

What happens if I only buy 5 of these T-Shirts? Is it still the same Flat Rate shipping as if I bought only 1 T-Shirt?

Annnnd those are all good points.
Each situation would be unique.

Adding this t-shirt to another order could be a flat additional charge.
Buying multiple of the t-shirt could be that the flat rate is good for the first item, plus a smaller additional charge per additional t-shirt.

Now that I see there are all these options, I'm assuming it's too hard to somehow set things up this way.

Fretty
https://www.universal-heros.com

Actually it is not horrible ...

You could set the Product weight to 0, then test in your shipping modules for UPS and USPS if this product is in the cart, and if so, build an extra charge based on the quantity to be added to the UPS and USPS charges for a mixed cart that contains this Product and other Products ... with a disable on these modules when only the T-Shirt is in the cart ...

For when it is the only Product in the cart, you could use Item Rate item and mange the cost based on the Item charge plus a handling charge ...

You just have to determine how much to charge for T-Shirt qty 1, and how much to add for each additional T-Shirt in the cart ...

That is some excellent advice.
Thanks!

Fretty
https://www.universal-heros.com