Polaroid Pack film with Field Cameras

Does anyone know whether Polaroid pack films can be used on Field Cameras (such as Toyo CF)?

Not being fmiliar with the Toyo CF, I did a search which landed me at the Robert White (U.K.) website. He shows the camera as having an "international" back which is what you need to use Polaroid pack films. Other field cameras may or may not have this type of back, also called "Graflok".

Well I use Fuji instant film on my Toyo.
You can use both "medium format" (FP-100C or FP-3000B) pack film with PA-145 holder
or 4x5 pack film (FP-100C 45) with PA-45 holder.
The equivalent of PA-45 holder for Polaroid is 550 and film 55X or 57X (still manufactured ???)

Sometimes the 405 or 550 holder is difficult to use with certain backs, even if they are all Graflock or International. And sometimes vertical use (pulling the dark slide) is prevented by knobs or camera parts -- so it is best to try a dry run before purchasing.

If they do work, the pack film is less expensive and slightly smaller than the full 4x5 frame.

Frank is right but difficulties happen with monorails because there are several parts protruding below the back. With both Toyo 45 and CF there is no problem (and I guess as well with every folding camera) at least with Fuji holders.
And you can use Fuji instant holders with graflocks or inserted like a regular holder.

One problem with using pack film (I'm thinking of medium format) on 4x5, is that it's off center.

I sometimes wonder why the pack film holders have never been designed to be centered on 4x5. I spent quite a bit of money to get a pack film specially designed for my particular camera, since other holders don't fit. Why couldn't it also have been centered.

If I'm using it to check for exposure on 4x5, I sometimes use shift or rise to correct for it's being off center.