As explained in an earlier post, the ink has to be cured. This is done by baking.
Do not rush. Follow your DPCB printer manufacturer recommendations.
I found that a cover to hold in the heat produces much stronger traces on the DPCB.
So placing a scrap of substrate over our board to be baked makes a significant difference, I believe.
There is not much clearance between the board being baked and that improvised ‘heat shield’ above. I would not try it during re-flow soldering.
So I cut up a piece of 4″ x 5″ substrate plated on one side, and soldered it to another whole piece. The copper clad side of the boards are placed on the ‘inside’ to help reflect the heat onto our project.
With this ugly little item there is no concern that we could disturb the carefully placed components before, or during, reflow.
For long term durability, use a big iron and 99.3/0.7 solder which melts at 227 C. (99.3% tin, 0.7% copper) to make this heat shield.