We offer 6 gram tubes and also 19.5 grams 6 inch tubes.
Only 50 colors are available in the 19.5 gram tubes for now. They are listed next to the same color in the 6 gram tubes.
If you "sort" the collection from highest price, you'll see them listed. In the listing title, it says "19.5 grams"
I hope this helps. We keep on adding to out website. Keep looking our contact us with your wish list of colors.
Merry, Bead Boss :-)