Greetings all. I have not commented any more based on my original message because I wanted to flatten a few more bottles of varying colors to see the results. The first time I used the Borax solution I got a lot of streaking from the soution then never tried it again. I flatten several more bottles over the past few days using the Borax solution and got very pleasing results with good transparency and no noticable div.
I applied the solution with a brush to all sides and bottom and allowed it to dry well before firing. The bottom side did not show any adverse affects so I am not sure why it was mentioned that the down side should not be coated. I fired the bottles on fiber board which allows better air flow under the bottle. Using thin fire paper or firing on the shelf itself may produce different results with a Borax coating on the underside so take this in mind. I have never tried the manufacture div spray so I do not know what to exoect from it. But anyway – I am gettting good results now, thanks to all for the comments.
High rivers and clear skies