When selecting the colour of cement to use for cementing a porcelain jacket crown, the powder being tested is best mixed with:

Self-cured and dual-cured materials can be opaque or translucent, and those indicated for cementation of ceramic restorations are usually provided in several shades. Light-cured materials are indicated for bonding of laminated ceramic veneers (esthetic cements) or orthodontic brackets. Some esthetic resin cements used for cementation of veneers include glycerin-based, water-soluble “try-in” pastes to help with shade selection. Reference: Craig’s 14th ed page no 289