You'll need to describe the current design of your table first. What does one record in the main table represent? Do you have a table of Vendors?
Of course! Apologies.
There is only one table that consists of info such as the style numbers (our style # and the blank style #), material content, embellishment techniques, # of colors used, division (men's, jrs, etc), and license. There is no table for Vendors, although there was already a field for Blank Vendor and for Embellishment Vendor. At the time the DB was first developed, the business was dealing with only one vendor for blank apparel and one vendor for embellished apparel; however, as the business has grown and changed, so has the amount of vendors it deals with. Now, for example, one t-shirt may have one vendor for a blank small t-shirt, another vendor for blank medium- extra large t-shirts, and yet another vendor for blank 2XL and 3XL t-shirts. There is also a seperate vendor that does embellishment, but there really may be SEVERAL different vendors that each do one type of embellishment.
I'd like to include something like a portal or tab perhaps added to the layout where the user may input price and date of price per size (for blank AND embellished apparel) and the vendor name.
Did that properly answer your question?
It sounds like you need to give significant thought to how you might restructure your database as part of gaining the add features that you want.
To start, a table for vendors would seem to be in order and another table for prices would make sense.
But even your current table sounds like something that should be divided into at least two, if not more tables. A Shirts table use a self join relationship to specify the "blank" shirts used and a related table might list all other details used to embellish that specific shirt.
Your relationships might look like:
Entities with the same color might be Tutorial: What are Table Occurrences? with the same data source table.
The pricing history records can include a date field and the relationship can sort by date so that the most recent price for a blank of a specific size supplied by a specific vendor is listed as the first related record.