Shipping Bottles with Washcloth as Favors

Hi all- We are about to start our Etsy shop and are in the final stages of finalizing listings, artwork etc. I’ve been trying my best to work this out myself but wondering if anyone has any solutions which I am not thinking of.

I am selling 4 oz glass bottles of liquid body wash with pump caps and custom labels as party favors. Based on my math, I can fit 36 of them in a USPS large flat rate box and 20 of them into a medium flat rate box. They’re all in bubble bags to help protect them from breaking on me. As an additional measure, I ordered cardboard dividers for the boxes (very surprised these are not more readily available for USPS boxes, or any boxes for that matter aside from larger ones on Amazon). The cardboard dividers fit within the box and each cell measures 2 inches x 2 inches which is perfect to fit my bottles. I’d be able to fit as many as possible to minimize shipping cost.

However, the problem is that I am planning to offer an add on feature if the customer wants where I roll up a washcloth, tie a bow around both the cloth and bottle to create a nice final favor. If I were to assemble this and ship as a finished favor they would not fit into my dividers and would cut down on the qty I’d be able to fit into each shipping box, increasing my cost significantly. Moreover, if I decide to not offer completed favors and send the washcloths as either pre rolled or even flat, I’m having a hard time figuring out how I’d fit them into the box and have it close for me since I don’t have much wiggle room.

My initial solution was to ship the bottles without the pump cap on, but then that would leave me having to find a way to protect the liquid from coming out.

Does anyone have a solution to this or a creative idea to prevent this issue? Are the cardboard dividers I ordered even necessary? Could I just maybe instead pack the bottles into the box and have the favors fully assembled but make sure they’re packed tightly? I don’t want any to break on me and I’d like a professional display when the customer unboxes the favors!

Thank you in advance!