A method of ion imaging comprising: automatically sampling a plurality of different locations on a sample using a first device arranged and adapted to generate aerosol, smoke or vapour from the sample, wherein said first device comprises a laser device; automatically translating said sample relative to said first device before and/or during and/or after obtaining mass spectral data and/or ion mobility data from at least some of said locations on said sample; providing a collision surface located within a vacuum chamber of a mass spectrometer and/or ion mobility spectrometer so as to generate analyte ions; adding a matrix to said aerosol, smoke or vapour prior to said aerosol, smoke or vapour impacting upon said collision surface; passing said aerosol, smoke or vapour into the vacuum chamber of the mass spectrometer and/or ion mobility spectrometer and causing at least some of said aerosol, smoke or vapour and matrix to impact upon said collision surface wherein at least some of said aerosol, smoke or vapour is ionized upon impacting said collision surface so as to generate analyte ions; obtaining mass spectral data and/or ion mobility data corresponding to each said location; and using said obtained mass spectral data and/or ion mobility data to construct, train or improve a sample classification model; wherein said matrix is selected from the group consisting of: (i) a solvent for said aerosol, smoke or vapour; (ii) an organic solvent; (iii) a volatile compound; (iv) polar molecules; (v) water; (vi) one or more alcohols; (vii) methanol; (viii) ethanol; (ix) isopropanol; (x) acetone; (xi) acetonitrile; (xii) 1-butanol; (xiii) tetrahydrofuran; (xiv) ethyl acetate; (xv) ethylene glycol; (xvi) dimethyl sulfoxide; (xvii) an aldehyde; (xviii) a ketone; (xiv) non-polar molecules; (xx) hexane; (xxi) chloroform; (xxii) butanol; and (xxiii) propanol or wherein said matrix comprises a lockmass or calibration compound. automatically sampling a plurality of different locations on a sample using a first device arranged and adapted to generate aerosol, smoke or vapour from the sample, wherein said first device comprises a laser device; automatically translating said sample relative to said first device before and/or during and/or after obtaining mass spectral data and/or ion mobility data from at least some of said locations on said sample; providing a collision surface located within a vacuum chamber of a mass spectrometer and/or ion mobility spectrometer so as to generate analyte ions; adding a matrix to said aerosol, smoke or vapour prior to said aerosol, smoke or vapour impacting upon said collision surface; passing said aerosol, smoke or vapour into the vacuum chamber of the mass spectrometer and/or ion mobility spectrometer and causing at least some of said aerosol, smoke or vapour and matrix to impact upon said collision surface wherein at least some of said aerosol, smoke or vapour is ionized upon impacting said collision surface so as to generate analyte ions; obtaining mass spectral data and/or ion mobility data corresponding to each said location; and using said obtained mass spectral data and/or ion mobility data to construct, train or improve a sample classification model; wherein said matrix is selected from the group consisting of: (i) a solvent for said aerosol, smoke or vapour; (ii) an organic solvent; (iii) a volatile compound; (iv) polar molecules; (v) water; (vi) one or more alcohols; (vii) methanol; (viii) ethanol; (ix) isopropanol; (x) acetone; (xi) acetonitrile; (xii) 1-butanol; (xiii) tetrahydrofuran; (xiv) ethyl acetate; (xv) ethylene glycol; (xvi) dimethyl sulfoxide; (xvii) an aldehyde; (xviii) a ketone; (xiv) non-polar molecules; (xx) hexane; (xxi) chloroform; (xxii) butanol; and (xxiii) propanol or wherein said matrix comprises a lockmass or calibration compound. <EOS>