do you need to sand it to make paint stick? I want a feathered finish for plaster

Thank you for posting your inquiry on DAP DryDex Spackling. As is the case with all wall/ceiling patching compounds, the final surface appearance of the product is contingent upon your application technique. Tooling or smoothing is required to initially place and shape the profile of the product to smooth surface appearance. As a final step, light surface sanding may be required to achieve the desired cosmetic finish. Sanding is not required to promote paint adhesion. Please note that most paint manufacturers will recommend or require the use of a primer (on bare surfaces such as new drywall and patching compounds), prior to the application of their topcoat paint finished. Should you have any additional questions or require further assistance, please feel free to contact DAP’s Technical Customer Service Department at 888-327-8477.