Printed matter, printing method, and printing device

1. A printed matter comprising:

a porous printing medium; and

a printed layer containing silver, the printed layer having a printed surface having an image clarity (2 mm), defined in Japanese Industrial Standards H8686-2, of 5.0 or more and a b* value in the range of from −7.0 to +4.0.

2. The printed matter of claim 1 , wherein the printed layer has an average film thickness in the range of from 50 to 300 nm.

3. The printed matter of claim 1 , wherein the porous printing medium has pores having an average pore diameter in the range of from 100 to 400 nm.

4. The printed matter of claim 1 , wherein the porous printing medium has a porous layer having a thickness in the range of from 1 to 50 μm.

5. The printed matter of claim 4 , wherein the porous layer contains at least one of silica and alumina.

6. The printed matter of claim 1 , further comprising a resin layer on the printed layer.

7. The printed matter of claim 6 , wherein the resin layer has a film thickness in the range of from 5 to 300 μm.

8. A printing method comprising:

applying thermal or mechanical energy to an ink containing silver particles; and

jetting the ink onto a porous printing medium to obtain a printed matter, wherein the porous printing medium has pores having an average pore diameter in the range of from 100 to 400 nm, and the silver particles in the ink have an average particle diameter in the range of from 15 to 100 nm.

9. The printing method of claim 8 , wherein the silver particles account for 1.0% to 15.0% by mass of the ink.

10. A printing device comprising:

an ink containing 1.0% to 15.0% by mass of silver particles having an average particle diameter in the range of from 15 to 100 nm;

a porous printing medium having pores having an average pore diameter in the range of from 100 to 400 nm; and

a discharger to discharge the ink onto the porous printing medium.

11. An inkjet printing device comprising:

an ink container containing an ink containing 1.0% to 15.0% by mass of silver particles having an average particle diameter in the range of from 15 to 100 nm;

a porous printing medium having pores having an average pore diameter in the range of from 100 to 400 nm; and

a recording unit to discharge liquid droplets of the ink by an action of energy.

12. The inkjet printing device of claim 11 , wherein the ink container is an ink cartridge.

13. The inkjet printing device of claim 11 , wherein the recording unit includes an inkjet recording head.

14. The printing device of claim 10 , further comprising a laminate coating mechanism to form a resin layer.