Some experiments are reported on how to get a 'user friendly' graphical display of results obtained from numerical constraint solvers available in 'Constraint Logic Programming; (CLP) languages, like e.g. Prolog III. For larger sets of result data graphical visualization is a suitable and desirable way to enable users to quickly perceive, understand, and interpret main features of these results. In particular the issue is addressed of whether it is preferable to utilize the built-in Prolog III graphics primitives or to use external graphic user interface packages. Related questions of data transfer and communication control are discussed. As present result it is stated that for a language like Prolog III emphasis should be laid on constructing robust and easy to handle interfaces to external software packages, rather than to rebuild all kinds of useful and desirable graphics features within the language itself. This report is a summary of the main results of one of the authors' Master's Thesis (Guibert 1993), enlarged by the study on 3D plots. It is a complement to work performed by ESPRIT partners within work package 5 ('Environment') of the PRINCE project (PRolog INtegrated with Constraints and Environment for industrial and financial applications - contract no. 5246). FAW's role in this project is to study suitable examples of CLP-technology in view of user applicability. (orig.)SIGLEAvailable from TIB Hannover: RO 9630(94005) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekCommission of the European Communities (CEC), Brussels (Belgium)DEGerman