sealant for letterpressed coasters

March 7, 2012 3:05 PM

I'm making some paperboard coasters, but I'd like to seal them so that they won't pick up coffee rings. What sealant would be best?

Here are the coasters I'm using (and here's an example of an early draft of the letterpressed final product, if you're curious!). Since a fair amount of work goes into them and I'd like to give them to friends, they shouldn't be completely disposable—they don't have to last forever, but it'd be great if they don't mark up and start to fall apart after just a few uses. Should I try Mod Podge? A spray-on sealant?

Thanks!

posted by you're a kitty! to sports, hobbies, & recreation (12 answers total)

Perhaps use clear plastic film with an adhesive backing, which you affix to the coaster and cut out the desired shape (and border edge). Apply two films, one on each side of the coaster, and then trim to taste.
posted by Blazecock Pileon at 3:08 PM on March 7, 2012 [1 favorite]

I've seen some DIY coaster instructions recently and all of them seem to have the same suggestion of sealing with a polyurethane spray.
posted by Falwless at 3:13 PM on March 7, 2012

My first thought was some kind of pour-on varnish or epoxy.
posted by Mister Moofoo at 3:15 PM on March 7, 2012

I asked this same question a while back and got some good answers. We used contact paper and didn't worry about sealing the edges, which has been not at all an issue (pressboard coasters seem to fare a lot better outside of pubs!)
posted by heyforfour at 3:35 PM on March 7, 2012

I'd go with a polyurethane spray as well. With a letterpressed product, I'd be worried that contact paper would either bubble over the impressed parts, or wrinkle if you tried to press it down into the impressions.
posted by amelioration at 3:41 PM on March 7, 2012

Polyurethane spray is good, but I've used Mod Podge for basically the same project with success.
posted by lovableiago at 3:47 PM on March 7, 2012 [1 favorite]

Wow, thanks everyone, and sorry I missed the old question, I searched for sealant but didn't even think to look for posts about coasters! Just goes to show me that few things are too specific for an ask :)
posted by you're a kitty! at 5:06 PM on March 7, 2012

I've used a water-based polyurethane for similar purposes (it was something I picked up in a craft store -- I forget what brand -- but same aisle as Mod Podge). A spray-on would work too, but I found the brush-on kind to be neater (and something I could do inside).

I do have to recoat mine ever so often (like every several months) but they hold up pretty well.
posted by darksong at 7:52 PM on March 7, 2012

How are you producing these? Are you having a local printer make them? If so, they could easily apply an aqueous coating to them that will help seal/protect them.

There is also this stuff, which has been a time-tested protectant used by graphic artists and hobbyists for ages.
posted by Thorzdad at 5:43 AM on March 8, 2012

Thorzdad - I'm printing them myself in a letterpress studio using oil-based inks.
posted by you're a kitty! at 7:57 AM on March 8, 2012

Maybe try Mod Podge? I frame this only as a question cause I'm not sure if it will make your inks run or smear. But I've used Mod Podge for a whole range of crafts cause its just that damn useful. People use it for shallacking different things & I actually used it to gloss over mixed media (magazine print + paint + newprint) coaster I was making and it worked amazing. And it comes in a few different finishes - though the matte I have still comes off a little shiny. Good luck!
posted by jay.eye.elle.elle. at 9:06 AM on March 8, 2012

Bitten by bad experience, gotta mention: The primary purpose of a coaster is to catch rings, drips, and condensation. Sealing the coaster to protect your design prevents the coaster from doing its job. Two of my tables now have water damage spots from glass-top photo coasters. The drips and condensation roll right off and onto the table. Please keep this in mind. It'd be awful to give these out as gifts and find out later that someone's furniture was damaged.
posted by xedrik at 9:57 PM on March 8, 2012