Porous particles with non-porous shell

1. A core-shell polymer particle comprising a common binder polymer for the core and the shell wherein the core has a porosity and the shell is non-porous and the particle has a porosity of from 10 to 70 percent.

2. The core-shell polymer particle of claim 1 further comprises pigments, waxes, shape control agents and charge control agents.

3. The core-shell polymer particle of claim 1 wherein the binder polymer is selected from the group consisting of polyesters; polymers of styrenes, monoolefins, vinyl chloride, vinyl esters, methylene aliphatic monocarboxylic acid esters, vinyl ethers and vinyl ketones.

4. The core-shell polymer particle of claim 1 wherein the particle has a size of from 2 to 50 microns.

5. A core-shell toner particle comprising a common binder polymer for the core and the shell wherein the core has a porosity and the shell is non-porous and the particle has a porosity of from 10 to 70 percent.

6. The core-shell toner particle of claim 5 further comprises pigments, waxes, shape control agents and charge control agents.

7. The core-shell toner particle of claim 5 further comprising colorants.

8. The core-shell toner particle of claim 7 wherein the colorants are selected from the group consisting of carbon black, aniline blue, calcoil blue, chrome yellow, ultramarine blue, Du Pont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, malachite green oxalate, lamp black, rose bengal, C.I. Pigment Red 48:1, C.I. Pigment Red 122, C.I. Pigment Red 57:1, C.I. Pigment Yellow 97, C.I. Pigment Yellow 12, C.I. Pigment Yellow 17, C.I. Pigment Blue 15:1 and C.I. Pigment Blue 15:3.

9. The core-shell toner particle of claim 5 further comprising release agents.

10. The core-shell toner particle of claim 5 further comprising flow aids.

11. The core-shell toner particle of claim 10 wherein the flow aids comprises from about 0.05 to about 10 weight percent of the toner binder weight.