Im trying to print a 100mm square lithophane  

RE: Im trying to print a 100mm square lithophane

First - soap and water to clean the PEI sheet.   Align the part so that the length is positioned front-back, so the bed movement is against the length, not the narrow part. Then - add a 12 mm brim to the print (24mm overall). 

RE: Im trying to print a 100mm square lithophane

Also make for small high thin prints,

a extra support,

make a square with 4 horizontal poles sticking at the object.

the print object place it in the y axis, and the extra support in the z axis, so it does not move.

In thinkercad you can make a support.

T his support you can load in your slicer, and move against your to printed object, also usable for other prints.

I made this as a example, you can make everything a lot smaller/thinner.

RE: Im trying to print a 100mm square lithophane

I just add modifier parts comprised of squares at each end to give it fins in a wide "H" shape (where the litho is the horizontal bar in the H). Since the style I print has a border and the border is hidden there's no issue with a little roughness from trimming it away. It may not help bed adhesion problems as much but it definitely cuts down on the wobble of the item as the print gets taller

RE: Im trying to print a 100mm square lithophane

Adding to the "make supports" group, You can add a 0.45 mm thick triangle at each end of the part. It comes off easily and acts like a brim, but no wobble.  No need for building anything complex.

RE: Im trying to print a 100mm square lithophane

I just want to let you know that I just finished my first lithophane and it is a success. You made this possible I dont think I would have got there on my own. I think what made a big difference was placing the model in the y-axis, the 12mm brim, and I changed pla and didnt run the first layer adjustment. I thought as long as I was using pla it wound not matter. Thanks for taking the time to help a newbie out.

Thanks alot, Gary