If you run into issues with a big flat print warping in the corners and you can’t seem to get it to stay stuck to your blue painters tape we have a simple trick that might help.
As always if possible redesign your piece to have small portions that break up long flat portions on the build plate and include recesses or other relief areas to make it smaller chunks of warping rather than one big area.
To make your prints stick to the blue painters tape you can simply apply a thin coat of UHU glue where your print will be and slightly further out to ensure you get the edges well. If you just need a tiny bit of help to make the print stick, tracing the outline of the print or even just a good coat in the corners can be sufficient. This glue stick is easy to clean up if you happen to somehow make a mess as it is water soluble.
This trick does apply to ABS on kapton as well. In both cases if you are still having issues it may actually be your tape lifting from the platform causing the warping. If so clean the platform with rubbing alcohol and apply a new sheet of tape.