Assign Custom product fields to select products

Hi, just installed Business edition for a client, never had a need for custom product fields, now I do.

I managed to create the custom field ok, but not sure how I get it to be "Assigned" to selected products only (Not across the board, can it be done by category?) and how to make it display on the product page and then into checkout etc?

You should create custom fields of the table "item", make them published on the front end and you will see them. In the options screen of the custom fields, you'll find a categories area where you can restrict the custom fields to only some categories.

Thanks Nicolas, was making it of the type product so it was not showing up.

Don't suppose there is an option to have the custom field appear depending on the selection of an option?

Like...

Personalised message - yes (Show Field)
Personalised message - no (Don't show field)

If both are custom fields, you can use the "Display limited" option for that.

Nope, one is an option as it needs to add a small cost.

In that case that's not possible.