Open time and slip are not fixed numbers outside field conditions. Paste thickness, backing, substrate absorption, water, waiting time, temperature and installer action change the result. A staged field record turns comments such as dries too fast or too slippery into comparable evidence.
Compare from one mixed batch
Record product, lot, powder and water weight, addition order, mixing, rest and completion time. For waiting-time comparison, use the same batch, application tool and similar coat amount so differences between separate mixes do not appear as open-time changes.
Create staged placement points
On one representative substrate, install equal wallpaper samples after planned waiting intervals. Record paste-application time, placement time and actual interval for every point. Choose intervals from product guidance and project needs rather than extending them only to claim a longer working time.
Describe slip with consistent criteria
Observe initial grab, movement with gravity, force needed to reposition, adjustment range, edge rebound and seam hold. Use one rating scale or short defined descriptions instead of only good or bad. Slip can support alignment but may also allow heavy wallcovering to move.
Record wallpaper, substrate and environment
State wallpaper type and lot, substrate, primer, surface condition, temperature and approximate humidity. Keep installer and roller or smoothing pressure as consistent as possible. If operators differ, record an identifier so technique is not confused with material behavior.
Review after drying before conclusion
Application feel does not replace dry inspection. Recheck seams, edges, bubbles, movement and surface condition and retain photographs. Hangzhou Karn supplies TDS and samples; any open-time or slip conclusion must remain limited to the recorded wallpaper, substrate, mix and environment.