sublimating coasters

[chris692424]

Hi, I've just started sublimation on coasters and having a few issues. The coaster is warping for some reason. Round's come out fine on 185c for 60 secs, but the Square ones seem to warp. Any idea why? thanks

[Justin]

We do a fair few of these, 197c 60 secs. Never seen warping with coasters.

What type of coaster is it?

[chris692424]

Hi, Square Hardboard from subliblanks. Think it might be moisture? I've used teflon top and bottom initially then added butcher paper.

[Mrteajunkie]

Hi, Square Hardboard from subliblanks. Think it might be moisture? I've used teflon top and bottom initially then added butcher paper.

My workshop is damp when it gets cold even running dehumidifiers 24/7 so I tend to pre press coasters to remove any moisture.

10 seconds at 180 is enough to solve any issues.
Although I’ve never had a coaster warp on more before.

[chris692424]

So 10 seconds prior to putting the design on? thanks. I'm beginning to think the problem is the coasters as they don't appear as flat as they should be. I can spin them around on a table.

[Mrteajunkie]

So 10 seconds prior to putting the design on? thanks. I'm beginning to think the problem is the coasters as they don't appear as flat as they should be. I can spin them around on a table.

Oh dear, they are warped.
Try some from xpres or mdp I use unisub coasters from them and they are perfect everytime.

[chris692424]

I thought so. I'll contact them this morning to see about a refund. Cork backed seem to be much better quality but more expensive. MDP don't have corked back unfortunately. Thanks for your response.

[Mrteajunkie]

I use the wooden backed coasters over corked.
try a few of each you will go with the wooden backed one in the end

[chris692424]

JUst thought the cork backed seemed better quality and don't slip?