add the cost of mailing tube to paper order

-- url of the page with the problem -- : www.mokuhanga-school.com.au/online-shop/...t/torinoko-mitsumata
-- HikaShop version -- : 3.5.1
-- Joomla version -- : 3.8.11

Is it possible to automatically add once per order the cost of a mailing tube when paper is ordered?
When other items are ordered, a tube is not needed. I placed a 3% margin on the shipping, which is ok for other items packaging, but not the tube.

Usually customers order multiple various items, Hikashop and the shipping plugin (until recently Australia Post V2) do a reasonable job compiling the weight & volume, however when paper is ordered there seems to be no way to include an additional single cost to that order?

The paper is sold in full sheets, which vary in size, eg 67cm x 91cm x 0.01m x 200gm (as set in the product weight and size)
I initially tried the rolled size and weight, but this created problems when more than one sheet is ordered. There is no difference in rolled volume between one sheet and 10 sheets - the volume is the size of the tube.

Note - website Hikashop is currently in catalogue mode while I am setting up in Japan..

Hello,

however when paper is ordered there seems to be no way to include an additional single cost to that order?

Thanks Mohamed
I will check it out..
Found this tutorial: www.hikashop.com/support/documentation/3...ng-manual-price.html

Terry