A new software tool for the support of cell projection in combination with variable shape electron beam lithography for mask making and direct write application is described. The program has been designed and developed for the WePrint 200, a new variable shape electron beam lithography system from Leica Microsystems Lithography GmbH, which includes a powerful cell projection unit. The WePrint 200 allows the use of 20 different mini-reticles with one set of apertures. Starting from the chip layout, Cellector calculates the layout structures which are potential candidates for cell projection and exposable using mini-reticles. The determination of the mini-reticle candidates takes place with consideration of the pattern neighbourhood relationship and the hierarchically layout description. For each mini-reticle, the program also calculates statistical values, like the number of calls per mini-reticle and the amount of flash reduction. These values help the user select the optimal mini-reticle set for the cell projection step. With the application of PROXECCO^1 The benefit of throughput enhancement using cell projection is directly correlated with the regularity of the chip layout and with the reduction of flashes by using mini-reticle. In the paper throughput enhancements by application of cell projection are given for different kind of chips.