Best way to keep sliced cake from drying out?

I've been having problems with a restaurant I supply with cakes. One of them is how the cakes are stored. They're kept in a case and customers (sit down and to go) order by the slice. When the cake is cut, the cut sides are left exposed and they dry out. I've talked to the owner about using pieces of cello up against the cut side. We use this at my PT bakery job on our bars of poundcake. The icing holds it right on and it really does keep the air off and the next slice is always moist. Anyhow, he basically ignored me, but I've had complaints about dried out cake from my friends who eat there so I've decided to try to enforce some kind of rule or I will stop supplying him. My husband talked to the owner tonight and brought up this point and he agreed to cover the cut sides from now on. But my hubby is wondering if there's another method that can be used that's easier b/c he knows this guy and his staff are pretty lazy about this kind of thing. I have NO ideas. I don't think it gets any easier than slapping a piece of cello up against the side after each time making a cut...???

Thank you to everyone for responding!

What makes this so difficult is that:

1). I can’t just make a different type of cake that is more moist; these have to be vegan cakes and the recipes I developed, while moist, can’t withstand being soaked in syrup. I have a fine mist spray bottle for my simple syrup (I don’t like dealing with the messiness of a pastry brush) and spray some on and that’s about it.

2). I can’t do the plastic dome thing because the cakes are in a refrigerator case and on display. Plastic Rubbermaid domes aren’t exactly pretty, unless there’s nicer ones out there? And true Wendy, it doesn’t mean someone will actually seal the dome!

3). I can’t pre-wrap them myself because I WILL have to charge more and Hari won’t pay anything extra. He was used to paying the old cake lady’s prices and mine are $3 - $6 higher per cake. Even though you get more portions from my cakes and he actually makes MORE profit off them, he ALWAYS forgets that part. Anyhow, if he doesn’t follow through with keeping them covered and I get any more complaints, I may have to wrap them myself and tack on the extra fee (if I lose his business, then oh well, but I want to give him a chance to do it himself first). How much extra should I charge for this if I completely wrap them in acetate? How much extra to cut and insert wax paper squares method? They are 9” cakes scored for 12 portions.

4). I considered individual desserts, but cost wise, it doesn’t work for him. If he can’t double the price, he’s not interested. And his customers are only willing to pay so much.

I did a delivery on Weds night. After the phone call with my husband, Hari was so polite and nice to me. I think it helped that my husband came with me to do the delivery. Side note: long story, but Hari has SCREAMED at me before to take things out on me because he had a bad day; so bad that as soon as I left, I drove around the corner and pulled over to bawl my eyes out (I had had a long day too). So I was scared to go alone and risk being screamed at over this (this is why I had my husband call him in the first place; I knew he would scream at me, but not at him). Anyhow, Hari asked me what kind of paper he should use. I couldn’t remember the name of the stuff we use at my PT job. I don’t think my boss would actually buy acetate since it’s so pricey, but it’s something similar. We just call it cello, but cellophane is that thin crinkly stuff and this stuff is thick. Anyhow, he asked me to bring him a piece of it in so he can show it to the guys at his restaurant supply store and get a roll. This is the most agreeable he’s been over the whole topic so I think he might actually be serious.

I want to move to a land where things like this aren’t even an issue! And where restaurant owners don’t scream at you because they had a bad day. Is there such a utopia?

Panini, the first 2 times I read that, I had no idea what the heck you were talking about. But after reading it for a third time, I get it! :D I'm going to dig around for plastic scraps and see what I can make. I've made a really cool dealy out of tofu containers that I use to press paneer in, so the Martha inside of me will come up with something.

Ya know Hogan, I would really like to blame the staff; I really would; but it's all on the owner. He doesn't enforce it and doesn't even do it himself and he personally serves out a lot of the cake. He has a new cook I'm getting to be chums with so the when Hari finally gets the acetate, I'm gonna have a demonstration: Acetate Application 101. Making them eat dried out cake is a good idea. Thanks for the tip!